Archive for the 'Computers' Category

Making Windows 10 look and act more like Windows 7 using LTSC, etc.

To start, I want to acknowledge that Windows 10 is a controversial subject – many people really like it, many people use it because it is what came with their PC, and some people fall into the “over my dead body!” camp. I’m in the latter group, and if you’re a Windows 10 fan this article is probably not for you. With that out of the way…

I really like the look-and-feel of Windows 7. It took a while to grow on me, but I’d happily keep running it if it was still in support and ran on modern hardware. But it isn’t, and it doesn’t. There was (IMHO) collusion between Microsoft and Intel to agree to not release Windows 7 and 8.1 support for newer processors and chipsets (citation here and a more user-friendly / less doublespeak version here). This was purely of academic interest until September 2019 when I purchased a Dell Precision 3630 with an Intel Xeon E-2286G CPU, which had just been released a few months prior. At that point I discovered exactly how incompatible this new hardware was. I was stuck with Windows 10 and had to make the best of it, which started me on a long journey of discovery.

Before I get into the details, let me list a few reasons I dislike the Windows 10 “out of box” experience:

  • It keeps changing out from under me, with features being added and removed and applications that stop working because they expect a particular release of Windows 10. A perfect example of this is the massive changes to the user interface in the 20H2 Windows 10 update. It continues the trend of “dumbing down” the visible portions of the system.
  • There is no control over what updates it installs or when it installs them – if you’ve been running a complex mathematical calculation or graphics rendering for several weeks Windows 10 doesn’t care – it is going to update and reboot whenever it wants to.
  • Even supposedly professional editions of Windows 10 like the “Windows 10 Pro for Workstations” that shipped with my Precision 3630 come with all sorts of unwanted things like Candy Crush, Cortana, Xbox, the Windows Store and more.
  • Extremely intrusive telemetry and advertising – is it unreasonable to expect that after paying over $300 for an operating system that I not be spied on and have an advertisement-free environment? Apparently.
  • The “Aero Glass” theme and UI effects were removed. I like the visual styling of Aero and don’t understand why it was removed. It certainly wasn’t for performance reasons as newer hardware has faster CPUs and better graphics. If Microsoft wanted to make changes just to be different, they could have retained the Aero theme as a user-selectable option.
  • Desktop Gadgets – Gadgets were deprecated during the Windows 7 lifecycle due to unspecified software vulnerabilities. Gadgets do run in a common environment (the sidebar.exe process) and have relatively unrestricted access to the system. However, I find the gadgets useful and have been running the same set of gadgets for over 10 years.
  • Metro UI – I’m lumping lots of unwanted stuff into this category – the new-style Start Menu, Windows Store and File Explorer to name a few. Again, change for change’s sake without an option to return to previous behavior.

Upon looking around, I discovered Windows 10 LTSC 2019 (Long Term Servicing Channel). This solves a number of the major issues from the above list, primarily by omitting unwanted [by me] features like games and the Windows Store, being frozen at the 1809 Windows 10 release, eliminating advertising and the more intrusive telemetry features, and allowing somewhat more control over the update process. It will also be supported by Microsoft for bugfixes and security updates until 2029.

Note that enough customers are apparently choosing LTSC that Microsoft announced that the next LTSC release (presumably LTSC 2021) will only be supported for 5 years instead of 10. Microsoft claims that this is because (quoted from the linked article) it provides “… a more consistent customer experience and better planning.” That sounds like classic doublespeak to me. In any event, I won’t have to worry about my LTSC 2019 installs until 2029. Yes, that means Microsoft will be supporting an older LTSC version for 3 years past the newer version’s end-of-life. Go figure…

LTSC sounds perfect, except that Microsoft doesn’t want you to be able to buy it. They go on and on about why you don’t want it. For example, “The Long Term Servicing Channel is not intended for deployment on most or all the PCs in an organization.” here, “The Long-Term Servicing Channel (LTSC) is designed for Windows 10 devices and use cases where the key requirement is that functionality and features don’t change over time.” here and so forth. Basically, if you’re not controlling an MRI machine or running a brewery (more on this below), Microsoft says “No LTSC for you!” and makes it extremely difficult to purchase. This completely ignores the fact that (from the Microsoft quote) “… the key requirement is that functionality and features don’t change over time.” That is exactly why I want to purchase it.

LTSC is not available from most distributors and if you ask Microsoft about it, they will claim (in my experience) that it doesn’t have a part number, can’t be ordered, and so on. That isn’t true – the part number is KW4-00190 and costs a little less than $300 when acquired through legitimate channels like CDW, Connection or Provantage. This is an upgrade license and you need to have an existing Windows 10 license, but even the “free Windows 10 upgrade from Windows 7” appears to count. Of course, now that you know the part number you’ll need to convince the distributor to actually sell it to you. There’s a bunch of paperwork that apparently needs to be manually processed at some points and most distributors don’t seem interested in going through the hassle unless you are purchasing a bunch of licenses (the minimum quantity I’ve found is 5). However, a number of people have succeeded in purchasing a single LTSC license plus 4 of the least expensive Microsoft licenses which are currently NK7-00031 (Microsoft Identity Manager – software assurance – 1 user CAL) for under $10 each. That gets you the minimum of 5 licenses to participate in volume licensing. Of course, if you need more than one LTSC license you can add them to your order instead of the “filler” CAL licenses.

While doing research for this blog post, I found an eBay seller who says that they are an authorized Microsoft Partner and Reseller (although Microsoft doesn’t provide any way to actually verify that), selling “Microsoft Windows 10 Enterprise LTSC 2019 for 20 PCs – Volume MAK” for $339.96 with free shipping. That works out to $17 per PC, which is a fantastic deal if this is a legitimate license. I’ve redacted the seller’s name and location from this screen capture, just in case it isn’t:


Click on the image for full-screen view

Assuming that you’ve managed to successfully purchase the licenses from somewhere and get them enrolled properly at Microsoft, you can then visit the Volume Licensing Service Center to register them to machines and download the installation media. In my case, I downloaded SW_DVD5_WIN_ENT_LTSC_2019_64-bit_English_MLF_X21-96425.ISO. If you are not planning on installing for US English, be sure to download the appropriate installation ISO for your locale. IMPORTANT: Do NOT download the 17763.107.101029-1455.rs5_release_svc_refresh_CLIENT_LTSC_EVAL_x64FRE_en-us.iso from the Microsoft Evaluation Center – that will give you an auto-expiring trial copy of an older base release that can’t be activated with a license key.

Once you have your copy of LTSC 2019 installed and activated, you may want to install the free O&O ShutUp10 utility, available here. This utility lets you disable or enable many Windows “features” that are either not controllable using Windows 10 built-in methods, or which require Group Policies to be applied (which are beyond the scope of this article). ShutUp10 gives you a clean interface which describes each function and an easy on/off slider to change it, as well as batch action buttons for things like “Apply only recommended settings”.

Now that you have a working Windows 10 install, you can take a look at it and decide if you’re happy with the look and feel of Windows 10 or if you would prefer it to look and act more like Windows 7 did. You can stop here if you’re happy with the way the system behaves, or you can read on if you’d like an environment a lot closer to Windows 7. Yes, this really is Windows 10:


Click on the image for full-screen view

I’ll discuss each of the programs I’ve used to get the comfortable look and feel of Windows 7.

The most important program is definitely Classic Shell from here. This free program does most of the “heavy lifting” to restore the Windows 7 style user interface. It is a newer version of Classic Shell, since Classic Shell ceased development in December 17.

Next is Gadgets Revived from here. This free program restores Windows 7 style sidebar gadgets to the desktop. As a bonus, it seems to have fixed the memory leak that affected the official Microsoft sidebar in windows 7 SP1 and later. Most of the gadgets you see on my desktop above are from AddGadgets.com. These free gadgets work with Windows 10 and Gadgets revived. Because Microsoft dropped support for gadgets, these have not been updated in some time, but they still work perfectly. The weather gadget on my desktop is from Win7Gadgets here, since both the Weather Underground and Microsoft weather gadgets have been nonfunctional for years now.

To round things out, I’m using the paid Glass8 Aero Glass add-on from here. While this is paid software, it is very inexpensive, starting at €3 (on the “Donate” link). Once you have paid, you will be emailed a link and password to be able to generate your activation key(s). Installing an activation key will remove the desktop watermark and enable automatic downloading of updates from Microsoft. Each time the Windows kernel is rebuilt by Microsoft, the location offsets (“symbols”) that the add-on uses to hook into the display manager and it needs to fetch the updated symbols from Microsoft. It’s very technical inside, but is very easy to use. You will probably also want to download the GUI for adjusting Aero Glass settings from here.

New WiFi for old laptops – the ALFA Network AWPCIE-AX200U

One of the issues when trying to use an older laptop (such as my Dell Studio 1558) in the modern world is the lack of high-speed WiFi cards – even the Intel Centrino Ultimate N 6300 is limited to a theoretical 450Mbit/sec rate, as it only supports 802.11a/g/n and not any of the newer WiFi standards.

Obviously, newer WiFi cards are available but they are generally in the M.2 form factor and not the Mini PCIe that older notebooks tend to have. These newer cards also come with a newer type of antenna connector (MHF4 instead of UFL). This means that the cards are not usable in older PCs without an adapter. These adapters are readily available from many sellers. Unfortunately, in many notebooks they won’t fit in the space available for the WiFi card. This picture shows how much space the adapter takes up:


Image courtesy of AliExpress

My Studio 1558 is one of the notebooks that doesn’t have enough room for that adapter. I thought I was out of luck until I discovered the ALFA Network AWPCIE-AX200U. This is a mini-size card that incorporates the Intel AX200 module, but with a Mini PCIe connector and older-style UFL antenna connectors. That card fits perfectly in my Studio 1558:


Click on the image for full-screen view

As you can see from that picture, even with the correct card things are a tight fit. You can also see that the 3rd antenna cable (grey, with a clear plastic cap on the end) is tucked away in the cable management channel. Unlike the N 6300 card, the AWPCIE-AX200U only needs 2 antennas. The card to the right is a DW5808 mobile broadband (LTE) card. Since the AWPCIE-AX200U is a WiFi 6 card, it operates on the traditional 2.4GHz and 5GHz WiFi bands and works perfectly with the antennas built into my Studio 1558. Other systems should generally be problem-free, but read the section on “things to note” below. WiFi 6E is the version of the spec that adds the 6GHz band. Intel has the AX210 card that adds support for the 6GHz band. But the 6GHz band (which actually extends up to 7.125GHz) is likely outside the range of older notebook antennas. So I don’t know if ALFA thinks it will be worth it to introduce a card based on the Intel AX210.

Here are the AWPCIE-AX200U and the AX200NGW side-by-side to show the difference in form factor:


Click on the image for full-screen view

And here is a close-up of the difference in antenna connectors:

Once I had the card installed, Windows detected the card correctly, but I decided to install the latest Intel drivers anyway. After that, I connected to my home WiFi network without any problem. Speed is unchanged as I’m running older Cisco Aironet 702i access points that don’t support the newer 802.11ac/ax standards required for higher speeds. At some point in the future I’ll replace them with some other type of device, but at the moment 802.11ax-capable access points (particularly ones with 10GbE LAN ports) are very expensive.

I did fire up MetaGeek’s inSSIDer app to see if there were any high-speed access points within range. The version of inSSIDer I was using (2.1, the last version before compulsory registration and activation) didn’t know about the newer standards, which was no surprise as it is over 8 years old at this point. So I bit the bullet and downloaded version 5.4 and registered it. As you can see, it detected an 802.11ax network at a speed of 2.4Gbit/sec:


Click on the image for the full image

The AX200 module (and thus the AWPCIE-AX200U) supports Bluetooth 5.1. The Intel documentation does not specify whether the Bluetooth antenna is internal to the module or if one or both of the external antenna connectors are used. Regardless, the Bluetooth radio sends and receives a good strong signal – it was able to “see” the televisions of several of my neighbors, a few houses away and had no trouble pairing with my test device (a JBL FLIP 5 speaker). I had to use Windows Device Manager to disable the Bluetooth 365 module that was already in the computer so there would only be one active Bluetooth radio. The BT365 module is in a location that requires near-total disassembly to get to, so I ran this way for a week. Eventually I needed to disassemble the laptop for an unrelated reason and took the opportunity to remove the now-unneeded BT365 module. Note that the ALFA website and the AWPCIE-AX200U datasheet both say that the module supports Bluetooth 5.0, not 5.1. This appears to be a typo, as the Intel datasheet for the AX200 clearly states Bluetooth 5.1, which is confirmed by this Microsoft support article. Performing the steps in that article shows that the AWPCIE-AX200U is using LMP (Link Management Protocol) 10, which is Bluetooth 5.1:

There are a few things to note before you run out and buy one of these cards for yourself:

First, some computer manufacturers (HP for example) have a “whitelist” of supported WiFi cards, which are generally limited to a bunch of overpriced, near-obsolete cards. Putting any unapproved card into one of those computers will give you an unfriendly message such as “Unsupported wireless network device detected. System halted. Remove device and restart.” You may have some luck searching for things like “<your computer brand and model> BIOS mod” or “<your computer brand and model> whitelist hack”. Of course, flashing an unapproved BIOS is something you do at your own risk. When considering future purchases, you may want to “vote with your wallet” and avoid purchasing any systems that try to impose this sort of needless lock-in.

Second, there is good deal of variation in what pins are connected on notebook Mini PCIe connectors. The AWPCIE-AX200U does its best to avoid conflicts by setting all pins not essential for operation to “Not Connected”. It is possible that some incompatibilities could still arise. If you post a comment here I’ll try to help you. Another issue is that the Mini PCIe USB pins may not be connected in your computer. In that case, the card will still work fine as a WiFi adapter, but the Bluetooth portion will not be detected.

If you’re interested in purchasing one of these cards, I highly recommend Rokland Technologies. They’re an authorized Alfa distributor and ship quite rapidly. Be sure to order the AWPCIE-AX200U card and not the AWPCIE-AX200 (no “U” at the end). The non-U card has the newer MHF4 antenna connectors and you will need adapters (and a place to put them) if you want to re-use your existing antennas.

Updated 23-Apr-2021 to include a side-by-side comparison of the ALFA and Intel cards and their antennas.

Studio 1558 overheating problem in detail

I have previously mentioned in passing, for example here and here, that the Dell Studio 1558 notebook computers are prone to overheating. I figured it was time to go into this in a bit more detail.

As I mentioned in the first post linked above, the configurations of some Studio 1558 computers (particularly ones with discrete graphics and quad-core CPUs) tended to overheat even when fresh from the factory. Dell addressed this with the A04/A05 BIOS which resolved the problem for most customers. However, people are still reporting the issue and selling used 1558 systems with comments like “The unit boots to BIOS, but a few minutes later it shuts off. No further testing has been done.” This is a different problem, caused by a combination of accumulation of lint in the fan and degradation of the heatsink compound over 10 years or so.

The fix is easy, once you get to the fan. Getting there is the hard part. Refer to the service manual (or DCSE if you have it) for detailed disassembly procedures. If you aren’t comfortable disassembling the system to that extent, most repair shops that fix laptop computers should be able to do this for you. I also offer this service, although I probably won’t be cost-effective for you unless you are having other services performed at the same time.

This picture shows the accumulation of lint that has built up over 10 years of use. The air exhaust through the cooling fins is completely blocked. The heatsink assembly was removed from the motherboard and the lint was carefully vacuumed out. Then the fan was removed and the whole heatsink assembly was put through an ultrasonic cleaner to remove any remaining lint. A new replacement fan was then installed.


Click on the image for full-screen view

Here you can see the hardened heatsink compound. It had hardened to the extent that there was almost no thermal conduction between the top of the CPU and the heatsink assembly. After carefully chipping away the larger chunks of material, the assembly was left to soak in solvent to remove the remaining compound. At the same time, the old thermal pads were removed from the part of the heatsink assembly that cools the HD5470 graphics chip and the 2 lower video RAM chips. The surfaces of the graphics and RAM chips were cleaned to remove the oils that had separated out of the old thermal pads.


Click on the image for full-screen view

The existing CPU chip (an i7-720QM) also had a large amount of hardened thermal compound on it. As this repair order also involved upgrading the CPU to an i7-740QM, no cleaning was done on this chip.


Click on the image for full-screen view

After installing the new CPU chip, all surfaces were cleaned with 2-part Arctic Silver cleaner / prep fluid. New thermal pads were cut from Arctic Silver thermal pad material (1mm for the 2 video RAM chips, .5mm for the graphics chip) and Arctic Silver heatsink compound was used on the CPU. After reassembly, the processor idle temperature is in the 49-51° C range and with intense CPU usage, reaches 76° C. The system has run under heavy load for more than 24 hours with no faults.

I can repair or upgrade your Studio 1558 (and other models, too)

As you can see from my many previous posts about the Dell Studio 1558 notebook, I can perform just about any repair or upgrade you might want:

  • Replace broken lid / hinges / power button
  • Replaced cracked or otherwise broken display screens, either with same type or an upgraded one – contact me for a free part compatibility check as some conversions will be more expensive than others
  • Repair or replace broken keyboard keys or trackpad buttons
  • Replace standard keyboard with backlit version or vice versa
  • Replace a keyboard in one language with one in a different language – most languages are available
  • Repair broken connectors (power, USB, video, etc.)
  • Fix overheating systems
  • Install BIOS with unlocked advanced menus
  • Replace hard disk drive or install a SSD (with all of your software and files copied over)
  • Conversion of various 1555 and 1557 models to 1558 models – frankly, with the low parts pricing I offer for 1558 work, you might as well go directly to the top-of-the-line 1558 configuration of your wildest dreams. I’ll reuse as many of the parts from your 1555 or 1557 as I can, to keep your costs low
  • Any upgrade at all – see my post “The Ultimate Studio 1558” for ideas
  • Have a cracked or scratched lid, or just tired of the style you have? Let me swap it for you! Many styles are available
  • Replacement 6- and 9-cell batteries available new from a trusted manufacturer in China, with a 1-year warranty on new replacement batteries as long as an appropriate Dell charger is used
  • Operating system installations (limited to clean installs – back up all of your data first or buy a new SSD and get your old drive back in a USB caddy if you desire)

I have a huge collection of spare parts, both new and used, as well as complete systems in a variety of configurations.

Service will typically be between $50 to $100 plus the cost of any needed parts (at great discounts!) and insured return shipping to you. A repair evaluation is free as long as you pay for insured return shipping. I can also provide estimates based on your description of the problem and pictures you provide, but be aware that “sight unseen” estimates are just that – estimates. The actual cost might be higher or lower once I evaluate your system in person.

I can also provide some repairs and upgrades for the Studio 153x models, but inquire first to make sure I have the needed parts on hand, as most of the 155x parts are incompatible with the 153x parts.

My standard warranty for repairs made with my “used recertified” parts is 60 days for the recurrence of the same problem and 120 days for repairs made with my “new” or “new old stock” parts. If a repaired or replaced component fails within that time period, it will be made right by me at no charge other than your cost to ship the system back to me – I cover the shipping and insurance back to you in this case. Any parts replaced under my warranty are warranted for the duration of my original warranty plus an additional 10 days as a goodwill gesture. So, if you have a repair with a 120-day warranty and it fails after 100 days, when your system is returned to you it will have 30 days of warranty left when you receive it – 20 carried over from the original 120-day warranty plus 10 days of goodwill warranty.

If you decide to provide your own replacement parts for me to install, you assume all responsibility for their proper functioning. Such repairs carry a 30-day warranty, solely on the work I performed, and there is no warranty on customer-supplied spare parts. I will endeavor to test your replacement part before installing it, but please understand this is a “reasonable effort” test and I might not discover all problems with your replacement part.

In no extent is any warranty to be construed as applying to the complete system unless you specifically purchased a rebuilt whole system from me – it is a parts and labor warranty for only the parts and labor performed and itemized on the repair invoice.

Feel free to contact me at: 1558repair@glaver.org

Instead of shipping your system to me, you can also drop off and/or pick up at our Hudson County, NJ location at no charge. Such appointments must be scheduled in advance for a mutually agreeable time. There is excellent service from many major bus lines and the PATH train (between NY and NJ) with stops near my office. Details can be provided if you tell me where you are coming from when you arrange the drop off of your system. This is only drop off and/or pick up service – business rules prevent me from allowing you to watch your system being worked on or waiting while it is serviced.

I generally do not sell individual parts, only a complete repair service. However, I usually have a limited number of certain parts available for sale: Scratch / dent / cracked lids, all guaranteed to be fully functional but not cosmetically suitable to be used for my repair purposes; various older models of WiFi / mobile broadband cards, etc.

IMPORTANT NOTE: If requested, operating system installs will be done with a legitimate disc and serial number, either sold by me or provided by you. I do NOT offer “cracked” or pirated Windows installations.

Studio 1558 drivers for Windows 10

As I mentioned in some other recent blog entries, I recently installed Windows 10 (x64) on my Studio 1558 computers. Note that this was a clean install on a formatted drive – if you do an in-place upgrade from an earlier version of Windows, things may behave differently.

Windows 10 (LTSC 1809 in my case) installed without any difficulty, but even after installing all of the Microsoft updates, some device drivers were still missing. As Dell never officially supported anything newer than Windows 7 on the Studio 1558, it isn’t a simple case of going to the Dell support page for the 1558 and downloading drivers. Some older drivers will install correctly, some will complain that they are for a different Windows version or will install but give errors when used. I have collected the device drivers needed to clear all of the “Unknown device” errors that show up in Device Manager. The system could possibly benefit from additional drivers such as the Intel chipset driver, but it functions perfectly without them. You may not need all of these devices – my 1558 has just about every option imaginable.

The drivers you may need are:

  • Wireless 365 Bluetooth module driver (says it is for the Wireless 380 module, works with the Wireless 365)
  • ST Microelectronics Free Fall Data Protection driver
  • Ricoh Card Reader R5C833, R5U230 driver
  • Dell QuickSet application
  • DW5808 LTE Mobile Broadband and GNSS driver
  • DW5808 GPS Rollover fix
  • DW5620 Mobile Broadband driver
  • Verizon Access Manager (VZAM) for DW5600 and DW5620 application (not needed for DW5808 card)

I am listing Verizon Access Manager for the DW5620 even though it is not strictly required – after installing the DW5620 Mobile Broadband driver, the cellular modem will show up as a usable device in Windows 10. However, if you rely on the native Windows support you won’t have access to the usage data that VZAM provides and as I mentioned in my post about the newer DW5808 module, Windows 10 has no native SMS support. The Mobile Broadband SMS Toolkit mentioned in that post works with the DW5620 as well, so you can use it to send and receive text messages.

I have installed each of these drivers on my Studio 1558 and they all work properly under Windows 10 x64. It is extremely unlikely that you are running the 32-bit (x86) version of Windows 10, since you’d be limited to under 4GB of RAM which will make the system pretty unusable – install the 64-bit (x64) version, even if you only have 4GB of RAM installed. Note that you can upgrade the Studio 1558 to a maximum of 16GB as I describe here.

I have verified that each of these files is downloadable as of March 2nd, 2021 via the link I’ve given. Vendors may re-organize their web sites, so if you are reading this at some point in the future, those links may not work. I have mirrored each of these drivers (with additional information in the filename so you can see what the file applies to) here. If at all possible, you should use the official vendor downloads and not the ones here since you don’t know if my files have been tampered with or not. I have verified the MD5 checksum (when available from the vendor site) with each of the files in my mirror.

DW5808 Mobile Broadband on the Studio 1558

I have been running DW5620 mobile broadband (cellular data) cards in my Studio 1558 notebook computers for many years. This is a 3G / EVDO card that will fall back to 1xRTT if a 3G network is unavailable. Although I have these cards activated on Verizon, they are no longer activating new 3G devices on their network – 4G is required at a minimum. This is so the existing population of 3G and older devices can “age out” and Verizon can re-use those frequencies for 4G and newer service instead, per this article in The Register. That article also says they intended to shut down their 3G network on December 30, 2020 although it appears to have been postponed for an unknown amount of time. The article also quotes a Verizon spokesperson as saying “Yes, our 3G network is still live today. We’re actively working with customers to migrate them to new technology. It’s not accurate to say the network will remain active ‘for some time.’ While we want to make sure we care for our customers – both consumer and IoT – our plan is to move them ASAP and retire the 3G network.” In any event, the writing was on the wall and it was time to upgrade the mobile broadband card in my Studio 1558.

I decided that as part of my Studio 1558 re-evaluation, 16 GB memory upgrade and Windows 10 install, that I would also upgrade the mobile broadband card to the latest possible. That is more difficult than it sounds because the newer cards are generally M.2 instead of the Mini PCIe form factor found in the 1558. The newest card I’ve found is the DW5808 (not the DW5808e) which is a Dell-branded Sierra Wireless MC7355 (PDF specification). That is a card that according to the datasheet supports LTE, HSPA+, GSM/GPRS/EDGE, EV-DO Rev A and 1xRTT. It is supported by all major US cellular providers, although I have only used it extensively with Verizon. I did test an AT&T SIM and it allowed me to connect to AT&T’s “sign up for mobile broadband service” page.

When purchasing one of these cards, it is preferable to purchase a new one as that guarantees it has never been blacklisted for being on an account that has an unpaid balance with a provider. A new card should also come with a manual and a full set of stickers. The stickers include the IMEI (taped to the top of the module) which is applied next to the SIM slot in the battery compartment, an FCC sticker (to be applied in the matching location on the inside of the 1558’s removable bottom access cover) and a Dell part number sticker (also for the inside of the cover). Here is a picture of what you should get, courtesy of eBay seller pcs_jec:


Click on the image for full-screen view

If you already have a mobile broadband card in your Studio 1558, you can simply replace it with the DW5808. Note that the antenna connections on the DW5808 are reversed compared to the DW5620, so be sure to re-connect the antennas in the proper locations. The center antenna connector is not used in this application. If you do not already have a mobile broadband card installed in your 1558, make sure that your system (primarily the lid) supports it and has the appropriate antenna connectors. You can refer to my blog post “Dell Studio 155x Wireless / Networking Options” here for more information. Here is the antenna connector layout from the Sierra Wireless “Product Technical Specification”:

Unlike the older DW5620 cards, a SIM is needed for service – if you don’t have one installed, trying to connect to mobile broadband will display the message “Insert SIM”. The advantage of this method is that you can just move the SIM card from computer to computer without needing to talk to your cellular provider about changing devices. One downside to the SIM location (in the battery compartment) in the 1558 is that it is a bit tricky to remove the SIM once it is inserted. Make sure to observe the correct orientation when inserting the SIM (there is a molded image of the correct orientation next to the SIM slot in the battery compartment). This picture shows the full-size SIM inserted in the SIM slot with the orientation matching what is molded into the case above the slot, in the center of the picture. You can also see the location for the IMEI sticker:


Click on the image for full-screen view

You will need the appropriate driver for your operating system. For Windows 10, that is “DW5808E and DW5808 LTE Mobile Broadband and GNSS Driver” from here. Windows 10 has built-in support for mobile broadband, but the Dell driver is still needed. Older versions of Windows needed an additional application to handle mobile broadband – for example, on Windows 7 with the DW5808 card, the “Connection Manager Application for DW5808/5808e/5809e/5570” application is required. On older cards like the DW5620 the application is usually provided by the cellular carrier. For example, VZAccess Manager (VZAM).

The one thing all of these applications have in common is that they are (for lack of a better word) “twitchy”. VZAM on the DW5620 would frequently report “card not detected” or fail to power the card on or off. The only corrective action at that point is to reboot and possibly power cycle the computer. I’ve run into this on multiple Dell and HP notebooks, even with factory-installed mobile broadband. Unfortunately, this behavior continues with the DW5808, at least in the Studio 1558. To be fair, neither Dell nor Sierra Wireless ever implied that this combination was tested by them. In my testing, either the board is detected at startup or it isn’t. If it isn’t, a reboot will fix it. Not really any different than the older DW5620 with VZAM. In further testing, this seems to be related to not having a SIM installed in the computer – I suspect the card is “bootlooping” trying to recover from a “no SIM” condition. All of the 1558/DW5808 systems I have that include SIMs behave properly – it is only the ones without SIMs that misbehave.

Like the DW5620, the DW5808 includes GPS functionality. Unlike the DW5620, the DW5808 does not make that functionality available as a COM port by default. A registry modification is needed. That is only for advanced users, but if you’ve gotten this far I think you qualify. The particular key is in HKLM > SOFTWARE > Sierra Wireless > QDL and you need to change the USBCOMP value from 9 to 8. The underlying reason is rather complex, but if you want more information I’d suggest starting here. As you can see from this screenshot, after changing the USBCOMP setting the DW5808 appears as a modem, as a network adapter and as 2 USB serial ports. DM is Device Management and NMEA is GPS:


Click on the image for full-screen view

The DW5808 and many other cards from the same era suffer from the “GPS Rollover” problem which causes the date to be reported incorrectly after November 3rd, 2019. As Sierra Wireless describes it, “The Global Positioning System provides positioning fixes and timing information to GPS receivers (such as MC73xx, EM73xx, WP75xx and WP85xx modules). The timing information includes a ‘week’ component represented as an integer value from 0–1023. This value will ‘roll over’ on 03 November 2019. As a result, the time reported to customer applications by MC73xx, EM73xx, WP75xx and WP85xx modules will be incorrect. (Note: Positioning fixes will not be affected.)” Since Windows uses the Windows Time Service and not GPS for setting the computer’s time, this is likely a non-issue for most users. However, Dell does provide a fix if you need it. Note that despite being described as “Application”, it is the one-time rollover fix and does not permanently install any software on your computer.

The Dell DW5808 Windows 10 driver installation also adds some Bluetooth device drivers, despite the DW5508 not including any Bluetooth hardware. This may be because the driver supports multiple card models. There is no Bluetooth hardware in the DW5808, so if you need Bluetooth support you’ll still need the Dell Wireless 365 Bluetooth adapter.

There doesn’t seem to be a native way to send or receive text or multimedia messages (SMS/MMS) in Windows 10. Microsoft offers the “Your Phone” Microsoft Store app which just links a Windows 10 PC to a cell phone and doesn’t use the internal mobile broadband adapter. There is a native Windows 10 (not Microsoft Store) utility called “Mobile Broadband SMS Toolkit” available here for free. Note that the developer is Russian and the web site is hosted in Latvia, so if you handle sensitive information on your computer you may want to further evaluate the situation before installing the app.


Click on the image for full-screen view

In addition to sending and receiving SMS messages, the app has quite a few other functions, including managing contacts and displaying a lot more information than Windows provides. As you can see, the “Current data class” is LTE:


Click on the image for full-screen view

Performance is quite good (measured with Ookla Speedtest). The DW5808 has a theoretical speed of 100Mbit/sec down and 50Mbit/sec up. I have never seen a download speed faster than around 40Mbit/sec. This could be due to a number of factors, including the computer lid not having the correct antennas for all of the frequencies used by this modem, or simply comes from network congestion (this is New York City, after all). Upload performance is quite good at 44Mbit/sec which approaches the theoretical maximum of 50Mbit/sec:


Click on the image for full-screen view

Studio 1558 BIOS with all features unlocked – improved thermal settings and more

One of the frequent issues people reported with the Studio 1558 when it was released was overheating. Some configurations were on the edge of reliability, particularly with the thermal pads Dell used, which weren’t ideal for the higher-power CPUs. Dell made some changes in BIOS A04/A05 to improve thermal management somewhat, but those settings are not user-configurable in the stock BIOS. Combined with the direction of airflow and the difficulty in reaching the fan for cleaning, that meant that airflow could be restricted by the surface the computer was used on and large balls of dust could also build up between the fan and the radiator fins.

People came up with all sorts of solutions involving polishing the heatsink, using expensive heat sink paste and even copper shimming. One of the things people reported was that the fan would never run at full speed, even when the system was close to overheating. The only time it ran at full speed was while flashing the BIOS! I have also found that using the computer with the optional 9-cell battery helps, as the 9-cell version elevates the rear of the computer by around 1″, allowing unrestricted airflow into the bottom vent. With the standard battery, there is only 1/8″ or so between the bottom of the notebook and the surface it is sitting on. Of course, regardless of which battery is installed, it is important to not use this computer on a soft surface or anything else that might obstruct airflow.

Way back in 2011 a user named “kizwan” on the Notebook Review forum posted a modified A11 BIOS for the 1558 and subsequently updated it to the A12 BIOS per my request. It enables all of the submenus present in the Phoenix BIOS. Not all of those features apply to the Studio 1558 and as these menus were never enabled in the released BIOS, there are typos. For example, the “CPU Control Sub-menu / LPC Control Sub-menu” is completely empty and “Clarksfield” is mis-spelled “Clsrksfield” in at least one place. Also, some of the explanatory text for some menu items wraps around to the left side of the screen. None of these cosmetic issues in BIOS setup affect regular operation of the computer as they only appear in BIOS setup.

It is possible that changing some of the now-visible additional settings could put the 1558 into a non-bootable state. In that case, just disconnect the AC power adapter and the battery, then open the user access cover on the bottom of the 1558 and remove the CR2035 coin cell. Push the power button on the side of the computer to discharge any remaining “flea power” and clear the CMOS settings, then reinstall the coin cell, replace the user access cover and reconnect the battery and AC adapter. On power-up, the BIOS should report that the CMOS settings are invalid and let you enter BIOS Setup by pressing F2.

There is one known interaction which may or may not present a problem – if you enable “VT-d Technology” in the “CPU Control Sub-Menu”, the computer cannot boot from removable USB media. This is not limited to the Studio 1558 BIOS – a number of other systems from the same timeframe have reported similar problems.

Here is the menu with the various fan temperature thresholds. In this picture I have changed the defaults to turn the fan on earlier and faster:


Click on the image for full-screen view

I have been running this BIOS for nearly 10 years and have not had an overheating problem, including in Death Valley when it was 126° F and several weeks per year every year since 2015 in the Mojave Desert where the temperature was always over 100° F. I do disassemble the computer annually to clean out the dust from the fan as well as blowing the desert sand out of the keyboard.

In case the MediaFire page vanishes, I have saved a copy of the file here. You can verify that the MD5 checksum matches the one in the original Notebook Review post.

The Dell Studio 1558 – Still a nice laptop in 2021

I’ve had a number of Dell Studio 1558 laptops for well over 10 years now. Occasionally people ask me “Why do you still have that old thing? You need a newer/faster/better system!” Actually, I don’t and I’m going to explain why.

The Studio 1558 (as I have configured or built them) has lots of still-relevant features, like:

  • Quad-core i7-740QM CPU with Hyperthreading
  • Discrete AMD HD5470 graphics
  • 16GB of user-expandable memory instead of being soldered in
  • Backlit keyboard with sculpted keys and 3 backlight intensity levels
  • Full-HD (1920 x 1080) screen w/ matte (anti-glare) finish
  • 1TB Samsung 860 EVO SSD
  • 6x Blu-ray recorder
  • Integrated 802.11a/b/g/n/ac/ax WiFi using Alfa AWPCIE-AX200U (based on Intel AX200) card
  • Integrated Bluetooth 5.1 (included with AWPCIE-AX200U)
  • Integrated 4G LTE universal mobile broadband using Dell DW5808 card
  • Integrated GPS (included with mobile broadband)
  • Built-in SDHC card reader
  • Built-in hardwired Gigabit Ethernet
  • 9-cell battery for extended runtime
  • Readily available schematics, service information and parts
  • Very attractive (IMHO) styling

However, being an 11 year old design, it does have some limitations. In approximate order from most annoying (to me) to least annoying:

  • Limited to 8GB RAM (not really – see my other blog post here)
  • Somewhat lower CPU/memory performance (see below)
  • Lower-end graphics performance for a modern laptop (see below)
  • SATA 2 interface for disk drive and optical drive
  • USB is 2.0, not a newer specification
  • “Gigabit” Ethernet tops out at around 600Mbit/sec
  • The last officially-supported operating system was Windows 7 (but it can run Windows 10 – see my other blog post here)

I don’t use this laptop for gaming, so the graphics performance isn’t a problem. I do some very light Photoshop editing when I’m on the road and posting pictures. The SATA 2 interface isn’t really limiting since I have a Samsung 860 EVO SSD with Samsung Magician software which boosts the speed quite a bit. The only time I miss having USB 3 is when backing up pictures / videos I took while traveling to an external USB hard drive for safekeeping, and that can happen overnight while I’m sleeping.

I’m going to compare the Studio 1558 with the closest-to-equivalent current systems from Dell.

First, let’s consider a Precision 7550 high-end workstation-class system configured as closely as possible to the specs of my Studio 1558 (PDF of Precision configuration here). That currently prices out at $3497.56 list price, $2439.33 sale price. While it has a faster CPU, memory and graphics, it has a keyboard with those annoying flat tops instead of sculpted ones like the ones on the Studio 1558. And it has no provision at all for an internal optical drive.

Next, let’s try a low-end system. Dell’s low-end systems are not customizable beyond selecting a stock hardware configuration with whatever software you want pre-installed. I selected the Inspiron 15 7000 as the model that came closest to the 1558 (PDF of Inspiron configuration here). After selecting 16GB RAM, 1TB SSD and a backlit keyboard, only one configuration remains, with a list price of $1659.99 and a sale price of $1409.99. Again, this has a faster CPU, memory and graphics but also the annoying flat-top keys and no internal optical drive. In addition, it lacks hardwired Ethernet (WiFi only), doesn’t support any mobile broadband options, offers no extended-runtime battery and probably has other drawbacks. It does have a higher-resolution screen than either the Studio 1558 or the Precision 7550 configuration shown above.

I’m picking Dell systems to compare with because they’re the ones I’m most familiar with, service manuals, parts and schematics are readily available, Dell doesn’t make you jump through hoops to prove you’re entitled to download drivers and BIOS updates, and doesn’t do silly things like having the BIOS only recognize officially “blessed” vendor-branded WiFi or other add-in cards. If you know of current non-Dell systems that are close to the Studio 1558’s configuration and reasonably priced, I’d like to hear about them in the comment section.

As far as performance of the Studio 1558, it is quite reasonable. Microsoft still includes the “winsat” benchmarking tool, though it no longer displays the scores on the Control Panel / System page. But if you know where to look:
%windir%\Performance\WinSAT\DataStore\* Formal.Assessment (Initial).WinSAT.xml
you can find the scores. Windows 10 rates the system on a scale of 1.0 through 9.9 instead of the 1.0 through 7.9 scale of Windows 7. Here are the results for one of my Studio 1558 systems running Windows 10:

Overall System Score: 5.1 (lowest of the following scores)
Memory Score: 8.5
CPU Score: 8.5
Graphics Score: 5.1
Disk Score: 7.75

For comparison, the scores on Windows 7 were:

Overall System Score: 5.7 (lowest of the following scores)
Memory Score: 7.7
CPU Score: 7.5
Graphics Score: 5.7
Gaming Score: 6.3 (no longer rated in Windows 10)
Disk Score: 5.9

That shows that a high-end configuration of a Studio 1558 makes a fine Windows 10 machine if you aren’t making extensive use of graphics. Just for comparison, this is the Windows 10 winsat result from a high-end (Precision 3630 with Xeon E-2286G CPU, 32GB 4-way interleaved RAM, Radeon Pro WX7100 graphics and a 1TB Class 60 NVME drive) workstation costing over $5000:

Overall System Score: 8.7 (lowest of the following scores)
Memory Score: 9.3
CPU Score: 9.3
Graphics Score: 8.7
Disk Score: 8.9

I’m happy with that.

Please note that the above benchmarks and my “seat of the pants” performance opinion is based on a system with an i740-QM CPU (this was the top-end CPU offered by Dell in the 1558), 8GB or 16GB of RAM, and a fast 1TB SSD running Windows 10 x64 LTSC. As part of the research for this article, I used a 1558 with an i5-520M CPU, 4GB of RAM and a 320GB mechanical hard drive, running Windows 10 Pro 20H2. Saying the overall experience was quite unpleasant would be a bit of an understatement. Simply restarting Windows had the disk saturated at 100% for well over 10 minutes as shown by the Task Manager / Performance window. A SSD would certainly have helped, but the 4GB RAM certainly caused a lot of paging activity. Given the cost of the upgrades today, it seems silly to not upgrade a Studio 1558 to a top-spec system.

With the computer running Windows 10 LTSC and Office 2019 Professional Plus, I felt it was only fitting to update the palmrest badges to reflect this. This is the original “Energy Star” sticker from 2010, but the CORE i7 badge has been updated to the latest style, the Windows 7 badge was replaced with a Windows 10 one, and an “Office 2019 Professional Plus” sticker was added to complete the display. The “Portable4” and “Backup PC” labels indicate the hostname on my network and that this is one of 3 identical Studio 1558 computers, one labeled “Real PC” that goes on the road with me when I travel, and 2 labeled “Backup PC” in case something happens to the real PC.


Click on the image for full-screen view

16GB RAM on a Studio 1558 is possible!

As part of an upgrade of my Dell Studio 1558 computers to Windows 10 (you can find all of my Studio 1558-related posts here), I decided to investigate the possibility of actually installing 16GB of RAM in each one. This is theoretically impossible according to Dell. So I checked the Intel Ark page for the Core™ i7-740QM CPU and it also says “Max Memory Size (dependent on memory type) 8 GB”. Pretty definitive, right?

Getting into the technical nitty-gritty, “Intel® Core™ i7-900 Mobile Processor Extreme Edition Series, Intel Core i7-800 and i7-700 Mobile Processor Series Datasheet – Volume One” (document number 320765-001, September 2009) is quite clear on pages 20-23 that the largest DIMM configuration supported is two 4GB modules. The “Intel® Core™ i7-900 Mobile Processor Extreme Edition Series, Intel® Core™ i7-800 and i7-700 Mobile Processor Series – Specification Update” (document number 320767-028US, February 2015) doesn’t say anything about support for increased memory sizes.

Not that that has ever stopped me before… I checked the Crucial web site (not that I’m a big fan of Micron/Crucial, but they are a memory chip manufacturer as well as selling memory modules) and they also list 8GB maximum memory, using 2 CT51264BF160B 4GB modules. This is a DDR3L-1600 part with 11-11-11 timing at that speed. That is a faster part than the Studio 1558 needs, since the fastest memory any of the CPUs in the 1558 need is DDR3-1333 with 9-9-9 timing. Fortunately, most things are perfectly happy with faster memory, even if they won’t make use of it. Cisco excepted, of course.

It turns out that Crucial makes that exact same spec of memory in an 8GB module, the CT102464BF160B. At only $37.95 each from Amazon, it seemed like a fun project to order two of these modules and see what would happen. And this was the result:


Click on the image for full-screen view

So far, so good. But what would the longer-term reliability be like when the system was heavily loaded? I decided to run Memtest86+ 4.20 (available here) to see:


Click on the image for full-screen view

At that point it had run solidly for 3 passes / 11 hours in Memtest86+. So I think it is safe to assume that this will work for the long term. This image also shows that the full 16GB is cacheable – sometimes when experimenting with oversized memory configurations only part of the memory is cacheable, leading to inexplicable random-seeming performance drops. Not shown in this picture, but displayed on another Memtest86+ screen, is that the memory is operating in fully interleaved mode, which Intel refers to in the datasheet as “Dual-Channel Symmetric Mode” which provides maximum performance. This is the same mode that 2 * 4GB memory operates as. so there is no performance loss with the larger memory.

Of course, Dell and Intel both saying that it is unsupported means that you’re doing this at your own risk. It is not like any of these notebooks or CPUs are still in production (or even under warranty) at this point, 10+ years later. IMPORTANT: I have only tested this with the 4DKNR motherboard (discrete ATI HD 5470 graphics) and an i7-740QM (S-spec SLBQG) processor with BIOS version A12. It may not work with other motherboards, CPUs or BIOS versions.

I have a number of theories as to why this was listed as unsupported:

  • At the time, 8GB memory modules were very rare in the SODIMM form factor. The memory controller (integrated on the CPU die in the i7-740QM processor) only supports 2 memory sockets.
  • Large-memory configurations were not that popular in Dell notebooks (at least in the Studio 1558 class) at the time. I’m told that the vast majority of Studio 1558s sold by Dell shipped with either 4GB (2GB * 2) or 6GB (4GB + 2GB) of installed memory.
  • Dell sold the Studio 1558 with a wide variety of CPUs with either integrated graphics or discrete graphics. It is possible that some of the CPUs or motherboards were actually limited to 8GB and it was just easier to say that they all had an 8GB limit. That doesn’t explain the Intel Ark pages also being incorrect, though.

I did try a pair of 16GB modules (the CT204864BF160B) and they did not work – neither a pair of modules for a total of 32GB nor a single 16GB module in either the DIMM A or DIMM B socket were recognized – all resulted in the 4 beeps indicating “Memory read / write failure”. It is interesting that the error was not the 2 beeps of “No Memory (RAM) detected”, so the system definitely determined that there was memory installed, it just didn’t know how to deal with it. Given that a) We’re talking about trying to fit 32GB in a 10-year-old laptop, b) Most new laptops ship with 16GB or less, and even Dell’s current Alienware gaming laptops have more 16GB models than 32GB models, and c) The cost of a pair of Crucial CT204864BF160B modules, which works out to around US $300 at present, makes it economically impractical to do, since for $300 you can get a very nice whole used Studio 1558 with discrete graphics, 1920 x 1080 screen, etc. I think any further pursuit of this and related stunts like trying a Core i7-940XM is the computing equivalent of “They’ve gone to plaid!” (click the link if you don’t get the Hyperdrive joke from the movie “Spaceballs”).

Reversing airflow on Cisco 3945 routers

The Cisco 3945 router ships with the default airflow “backwards” (back-to-front) compared with all other standard Cisco routers and switches. While back-to-front is available on a number of Cisco producta, as either a factory option (for example, the Catalyst 4948E-F) or as a field conversion (for example, the Catalyst 4500-X-16SFP), the 3945 is the only Cisco device I’ve encountered which defaults to a back-to-front airflow. There is an optional fan assembly (3900-FANASSY-NEBS) which has front-to-back airflow, but it is hard to find and represents a large additonal expense, since your 3945 presumably has a fan tray already that is working perfectly (but backwards).

This article shows how to convert a fan tray from the standard 3900-FANASSY to 3900-FANASSY-NEBS with the only new part required being an inexpensive (pennies) jumper and your time to do the conversion. NOTE: While it is possible to do this (with practice) by removing the fan assembly from a running 3945 and converting / reinstalling it before the 3945 shuts down from overheating, I suggest that you power down the 3945 first to avoid the problem. If you are converting multiple units, you can shuffle converted and un-converted fan assemblies with no downtime.

You will need the following tools and supplies:

  • Small needlenose pliers
  • Small diagonal cutters
  • Phillips screwdriver
  • Several small cable ties
  • Fan mode jumper (more on this below)

The “fan mode jumper” is just a short (1″ or so) length of wire with the correct pins on each end. The pins are Molex part number 39-00-0039, 18 cents each. The tool to crimp them is Molex part number 64016-0200, which is quite expensive at $137.21. However, you can get creative and use the small needlenose pliers to manually crimp the pin onto the cable. If you do this, I suggest also soldering the pin to the cable (after crimping) to ensure a good mechanical and electrical connection.

This is the jumper wire and the small cable ties (each picture is clickable to show a higher-resolution version):

Following the Cisco instructions, remove the bezel and the fan assembly from the router. Place the fan assembly face-down on your work table and remove the 8 Phillips screws holding the two halves of the fan tray together, as indicated by the circled red areas in this picture. Your fan tray may or may not have screws in the circled yellow areas; you do not need to remove those. This is a new spare fan tray – your fan tray will likely be a lot dustier:

Carefully separate the two halves of the fan tray. One piece is only sheet metal – set that one aside for later. The other piece has the fans, wiring, and connector. That is the piece we will be working with. There is also a small clear plastic light pipe, as shown in this picture. Carefully remove it and set it aside for later:

Each fan is held in place with 4 blue silicone rubber stakes. Here is a view of one of the fans:

Starting with the rightmost fan (numbered 4 in the stampings on the tray), using the needlenose pliers, gently squeeze the expanding “V” part of the stake and carefully lift that corner of the fan up. Repeat with the 3 remaining corners of the fan and lift the fan out:

You may need to use the small diagonal cutters to cut a cable tie holding the fan wires in place if you don’t have enough slack to perform the next step. Flip the fan over so what was the top of the fan is now on the bottom (one side will have a part number sticker while the other side will be blank). Re-install the fan on the 4 blue silicone rubber stakes, and while gently pulling on the free “tail” of the stake, push the fan down against the metal of the fan tray until the expanding “V” part pulls through the fan. Repeat for each of the 4 remaining fans.

When you have the next-to-rightmost fan out, you will see the back of the connector that connects the fan tray to the router:

The red arrows in the previous picture show where the jumper needs to be installed. Bend the jumper into a “U” shape and carefully insert it into the connector until it clicks. You should end up with it looking like this:

Once you have all 5 fans flipped over, examine the underside of the fan tray to make sure there are no wires sticking out and that the fans are all fully seated on the blue silicone rubber stakes. An un-seated stake will generally appear slightly “popped out” when you look at the underside of the fan tray.

Use the small cables ties to replace any ties you had to cut to get enough slack to flip the fans over. Next, re-install the light pipe. The small U-shaped bend lines up with a matching protrusion on the sheet metal, shown with an arrow in this picture:

Carefully re-install the other sheet metal half of the fan tray that you set aside at the beginning. You may have to wiggle the light pipe a bit to get it to line up with the holes in the fan tray. Make sure that the two halves of the fan tray are fully seated on each other with no protruding pieces (there are interlocking metal tabs on the two halves). Also make sure that no wires are sticking out or being pinched. If all looks good, re-install the 8 Phillips screws. Give the fan tray another look-over to make sure everything is in place, then re-install it in the router and power up the router. Once the router has booted, use the “show environment all” command to verify that all 5 fans are operating correctly and that the router has detected the new jumper and is operating in front-to-back mode:

SYSTEM FAN STATUS
=================
 Fan Tray: Installed with Reverse Air Flow. Air Filter Supported.
 Fan 1 OK, Low speed setting
 Fan 2 OK, Low speed setting
 Fan 3 OK, Low speed setting
 Fan 4 OK, Low speed setting
 Fan 5 OK, Low speed setting

Technical minutiae: The only thing the jumper does is tell the router that a front-to-back airflow fan tray is installed. If you don’t install that jumper, the router will still operate with front-to-back airflow but the environmental readings will indicate that the unit is an “air conditioner” (exhaust air is cooler than intake air):

SYSTEM FAN STATUS
=================
 Fan 1 OK, Low speed setting
 Fan 2 OK, Low speed setting
 Fan 3 OK, Low speed setting
 Fan 4 OK, Low speed setting
 Fan 5 OK, Low speed setting

SYSTEM TEMPERATURE STATUS
=========================
 Intake Left temperature: 18 Celsius, Normal
 Intake Right temperature: 17 Celsius, Normal
 Exhaust Right temperature: 16 Celsius, Normal
 Exhaust Left temperature: 17 Celsius, Normal
 CPU temperature: 49 Celsius, Normal
 Power Supply Unit 1 temperature: 21 Celsius, Normal
 Power Supply Unit 2 temperature: 22 Celsius, Normal

As you can see, exhaust air is being reported as 1 degree cooler than entering air. This is because the router doesn’t know the airflow is reversed, so the sensors behind the fan tray are being treated as exhaust and the sensors by the rear I/O panel are being treated as intake. Installing the jumper lets the router know airflow is reversed and that it should report the rear I/O panel sensors as exhaust and the sensors behind the fan tray as intake:

SYSTEM FAN STATUS
=================
 Fan Tray: Installed with Reverse Air Flow. Air Filter Supported.
 Fan 1 OK, Low speed setting
 Fan 2 OK, Low speed setting
 Fan 3 OK, Low speed setting
 Fan 4 OK, Low speed setting
 Fan 5 OK, Low speed setting

SYSTEM TEMPERATURE STATUS
=========================
 Left Intake temperature: 20 Celsius,  Normal
 Right Intake temperature: 18 Celsius,  Normal
 Right Exhaust temperature: 20 Celsius,  Normal
 Left Exhaust temperature: 21 Celsius,  Normal
 CPU temperature: 61 Celsius, Normal
 Power Supply Unit 1 temperature: 23 Celsius, Normal
 Power Supply Unit 2 temperature: 25 Celsius, Normal

Note: the two “show environment all” reports above were performed at different times, thus the differing temperature readings. There is no difference in cooling efficiency when reversing the airflow direction.