PC Power & Cooling “Silencer 500 Dell” Review

As I mentioned in my previous post, I had a power supply fan fail in one of my Dell Optiplex 755 systems. Although I received a replacement supply from Dell (the system is under warranty for another two years) I decided to look into a larger power supply, as I’d upgraded the hard drive, CPU, and video card. The standard Dell supply is only 305 watts and I expect it is running near its rated capacity.

I’ve been using PC Power & Cooling products since the company was founded – the first product I used was a fan that bolted onto the back of an IBM PC XT to improve airflow. I haven’t used their products recently, as the few systems I’ve built from scratch have come with power supplies already installed in the cases.

I took a look at their site and found the Silencer 500 Dell power supply which stated that it was a direct replacement for the Dell power supply in my Optiplex 755. It also said it was a direct replacement in 61 other Dell systems, which should have given me a clue that the unit was more generic than it was letting on.

This power supply slightly exceeds the efficiency rating of the stock Dell power supply (82% vs. 80%) while providing up to 500 watts continuous power.

I unpacked the power supply, which came in a nice printed box (my earlier PCP&C supplies had come in generic brown cardboard boxes, which indicates how far power supplies have come in being recognized as a critical component of the system). There was a huge wad of cables coming out of the supply – far more than the Optiplex 755 needed.

I did a test fit of the supply in the chassis and discovered that there were a number of problems. First, the AC power cord connector interfered with part of the case. Next, the case had tabs which were designed to slot into the Dell power supply. The PCP&C supply was lacking those slots, so it was impossible to mount the supply perfectly squarely in the case.

The first change I made was to modify the AC power cord connector on the supply so it would fit in the case. This involved cutting off the plastic “ear” on one side of the connector. Fortunately there is a metal tab on the connector which will help retain it once the power supply is installed in the chassis:

Next, I had to come up with a plan to deal with all the unused power cables:

My first idea was to tie them up neatly in the space between the power supply and the back of the DVD drives:

However, it was a very tight fit and it severely reduced the airflow through the power supply, as the vents on the inside face of the supply were nearly completely obscured by the mass of cables.

As I had already voided the warranty by trimming the power connector, I decided to open the supply and remove all of the un-needed cables. I could have cut them off outside the supply, but then I would have to individually insulate all of the cut ends and it would be really ugly.

After a brief round of cutting, the excess cables were removed:

As part of this process, I removed the floppy drive power connector (mini 4-pin) and installed it on the end of one of the SATA power cable branches. As supplied by PCP&C, the floppy connector is at the very end of a long chain of full-size 4-pin connectors (used for legacy hard drives and CD-ROMs, of which this system had none). I trimmed one of the SATA power cable branches to 2 SATA power connectors and installed the floppy connector at the end. I also removed the last connector from the other SATA power cable branch, leaving 2 connectors, and routed it down to the hard drive bay in the system. This produced a set of cables that was far more manageable:

I don’t recommend doing this yourself – aside from voiding the warranty, you could easily damage the power supply or injure yourself. PCP&C says that they don’t believe in power supplies with modular cable systems (see FAQ #3 here). However, as long as they are going to continue to represent the supply as fitting 62 different Dell models, they need to come up with some system to deal with un-needed cables. Also, it is important to remember that there are already a pair of connectors on each cable – one on the cable end and the other on the device it is plugged into. PCP&C has no control over those connector styles as they’re dictated by industry standards. But they would have unlimited choices for modular power connectors if they decided to use them.

Also, while they could justify the cables by saying that they don’t know what cards and peripherals a customer might have, there is no excuse for the interference of the power connector with the PC case – this is clearly a case (no pun intended) of someone looking at the specs of the Dell power supply and saying “sure, ours will fit” without ever checking it for themselves. It should be possible to move the power connector closer to the center of the power supply without requiring a complete re-design of the power supply and without imparing the fitment in the other Dell cases. PCP&C offers custom power supplies, but I shudder to think what the cost would be for a one-off solution to the problems I encountered.

While I’m satisfied with the solution I came up with, I can’t recommend this supply for use in the Optiplex 755 (due to the power connector mounting issue) or in any other space-limited Dell enclosure (because of the large number of un-needed cables).

7 Responses to “PC Power & Cooling “Silencer 500 Dell” Review

  • 1
    January 5th, 2010 05:08

    Hey dude.

    Well, to start off.. firstly.. I am a lazy person.. and I don’t really read stuff.. but I am also a dumb person who won’t understand easily either.. so I need your help mate.

    I needed to know that is this.. the Dell Silencer in your picture, being equipped in the Dell Optiplex 755 SFF??

    Because.. I have a SFF (Small Form Factor). And.. I need to upgrade my pc.. to play new games, yes.. I am a gamer, also a teenager. I don’t get most of this stuff.. so I need your help.

    So.. anyway, like.. I needed to know.. All these articles are about Dell Optiplex 755 SFF? If so.. I am amazed. I just need your response so I buy these stuff, and upgrade my PC!

    Also.. my dad can install everything else if he just gets some answers. Which, you can help me only.

    So please respond me soon.

    Thanks in advance!

    – Dan

  • 2
    Terry Kennedy
    January 5th, 2010 05:45

    This article is about the “Mini Tower” version of the 755. Some of the people who have posted comments on my other 755 articles have different versions, though I only have the MT myself. I don’t think this particular power supply fits the SFF version – the PC Power & Cooling web page for it only lists the MT.

  • 3
    November 17th, 2010 20:20


    Good article, but I was wondering after I saw the pic of the PS installed why you just didn’t notch the case instead of cutting off the ear of the AC input socket?

    I have followed (lurked) your O755 adventures and have applied most of your tips to my own system.

    I have the 425w PS and am running a Q9550S (lower TDP than the Q9550), with a 1st gen Intel X-25 80GB for the OS (Win 7 Pro x64), and 2 1TB Seagates in a RAID 0 array for storage of everything else. 8Gb of ram.

    I opted for the Nvidia 9800 GT card and it has been adequate for running even the problematic Fallout 3 game.

    I just bought two XFX GTS 250 cards and was hoping to SLI them together. Not sure at this point if that will work given the 425w PS, so was looking to bump that up a bit to the 500w.

    I will likely try this Silencer PS if I find that the 425 just doesn’t cut it.

    Thanks for the great blog!


  • 4
    Terry Kennedy
    November 18th, 2010 01:51

    The O755’s were still under warranty at the time and I wanted to be able to put them back to the original configuration if I ever needed to. Hence modifying the power supply instead of the case. Also, I needed to do a lot of work removing and shortening the PCP&C power supply cables, so it made sense to modify its power connector as well.

    I’m running some O960’s (also the Small Mini Tower form factor) with pretty much the same components as shown in my O755 upgrade entry, but with a pair of Crucial C300 256GB SSD’s instead of the Velociraptor. I’m using the Dell C921D 425W supply and it seems to work fine. The PCP&C supply has been discontinued – their web site now lists it in the “End of Life” section.

    There’s only one PCI Express x16 slot in the O755/O960, so I don’t think SLI / CrossFire is an option for those systems.

  • 5
    October 2nd, 2011 18:09

    My Dell Optiplex 755 won’t start and the yellow power button is flashing. After using a paper clip to jumper the power supply, the fan didn’t run. Is there a power supply you would reccomend as a replcement?



  • 6
    Terry Kennedy
    October 2nd, 2011 18:29

    @cddalton – it mostly depends on which size chassis your 755 is. If it is the mini tower (SMT) like mine, the Dell C921D is a decent upgrade at 425W, and has a few extra (and longer) power leads for expansion cards, etc. I know that supply fits in the 755 SMT without needing to do any weird cutting of the case or supply. I believe Dell changed from their bizarre proprietary power supply pinout long before the 755, so any generic ATX12V 2.0 power supply should probably work. I’m not near my office and won’t be for a week or so, so I can’t check to see if the 755 requires -5V, which was removed from later ATX specs. If so, that limits you to older models of power supplies. I’d also suggest up-sizing a generic replacement supply to 350W or higher, even though the 755 shipped with a 255W supply. Newer supplies deliver peak power at different voltages, and the extra capacity may help prevent problems from a mismatched supply. Of course, the C921D is a drop-in and doesn’t have any of these potential isues.

  • 7
    October 2nd, 2011 18:53

    I have the Mini Tower so the Dell C921D looks like a good option. – Thanks.

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