Dell GX620

[midibob]

Out of interest I've just been told that the newer GX750's now have a small fan attached to the underside of the hard disk carrier. How far this will go to stop the caps suffering remains to be seen.
Obviously Del have taken note of the 620 failures!

Bob

[computernut]

New to the forum:
I have 7 Dell GX620 USFF computers in the network. They are all just out of warranty. 3 of the 7 have had the caps blow. I have replaced the moboards in all 3 so far. So I have 3 moboards I want to get recaped.
Question Can they be capped without the Processor and memory on the board and be sure they will work? The reason for that is that the computers are in use in a business enviroment.
I have included Pic's of the motherboards and put a red dot on each cap that show signs of leakage and/or bulging. The first two computers would not even start. The last computer would post but hang up and give the message that there was no boot drive.

Thanks
Chet

[370forlife]

God those things must get really cooking in order to blow out rubys.

You should recap without processor, ram, etc... in it. Though a few people have done it with processor in with success.

[computernut]

Do you know of anyone doing the re-capping. I don't know if I want to try it or not. I has been ages since I have done serious soldering. I put in a request to Chris at "Administrator" <[email protected]>
but have not heard anything back yet.

[370forlife]

http://www.badcaps.net/pages.php?vid=15

That is what you should fill out, but remember that he is usually pretty busy.

[PCBONEZ]

GX620 have heat issues due to poor air flow design.
There is another thread on them in here somewhere.
-
If you want them to last longer the second time around the best thing to do is work out a polymer upgrade for the boards. Cost will probably be 2x to 3x that of using electrolytic caps but the odds are you won't have to recap again later and with lytics you likely will have to.
You will have to [should] take voltage readings on the caps you are replacing because it's common to use 6.3v lytics on small voltages like 1.5v-3.3v and with poly you can use lower voltage caps. [2.5v and 4v poly are much less expensive tha 6.3v poly. - But you HAVE to make sure the caps voltage rating is the same or more than the actual circuit voltage. For example don't use a 4v cap on a 5v circuit.]
-
You could also try it improve the air flow but you need to drill some air vent holes in strategic locations [dead flow areas] and that might not 'look to pretty' to people that lift their pinky when they sip coffee/tea.
.

[midibob]

A point to note on these boards is not to forget the 220uF caps. Although they don't blow like their larger cousins they do dry out and I have had many instances of them being high ESR to completely open circuit.

Bob

[drueter]

I can confirm that the Dell GX620 motherboards do develop a problem with capacitors. Specific symptoms, from my personal experience:

• System becomes unstable / locks up periodically (1-2 times per day)
• Event log shows hard drive controller errors: Source: Disk / Event ID: 11 / The driver detected a controller error on \Device\Harddisk0\D
• Hard drive controller errors reported EVEN ON NEW PCI SATA CONTROLLER--not just the on-board controller!
• Hard drive transfer mode is degraded from DMA to PIO--which is MUCH slower, and causes other problems
• USB gets flakey, such as: USB keyboard / mouse go unresponsive, even though system can still be accessed remotely via RDP
• USB gets flakey, such as: USB-attached hard drives spontaneously disconnect / have delayed write failures, etc.

On my board, there were 4 capacitors that exhibited visible signs of deterioration: bulging caps and corrosion. (3 were 2200 mf and 1 was 1800 mf). Others may be failing too--those were the only ones with visible indication of problems.

My system was purchased July 24, 2005--and began having noticeable problems about June of 2009--almost 4 years to the day. (System used as main workstation / daily use / powered on 24 x 7. Replaced power supply once due to failed fan, had been running 4 gig of ram and Seagate 320 gig Barracuda drive.)

See attachment for photo of capacitors on my board.

I spent many hours slogging through these system problems before replacing the motherboard. A motherboard failure seemed unlikely to me--especially because the system still ran. In my case the symptoms got progressively worse over a period of several weeks. But swapping out the motherboard resolved all of these problems.

I hadn't heard of the capacitor problem before. Thanks badcaps.net for the information here!

[computernut]

Yep!! I think we are just seeing the tip of an iceberg on these cooking CAPs. I just wish someone would come out with a kit and offer install. But maybe there is not enough gone bad yet.
I have had 3 go belly up and bought motherboards from http://www.cygnussupply.com They have excellent service!! I bought the refurbished because they are less expensive and all 3 motherboards worked great. Just be sure to order the right ones. Be sure to check the motherboard for the part number. Mine was
U8811 Dell System Board ( Motherboard ) w/Tempan, OptiPlex GX620, USFF Yours may be different.

[BarryS]

Have just had capacitor c402 fail on a 620 usff, Dell want 250GBP to replace, will be cheaper to buy a newer machine with a longer warranty.

[PCBONEZ]

Probably Not.
New machine may have same or a new problem.
-
Learn to solder and then you can fix it for less than lunch costs.

[lightingguy32]

What I encountered over the summer is that many of the GX620s that we have reimaged have been tagged as having their power supply units replaced. Also from reading online, there seems to be a problem with several caps in the GX 620 PSU that dell has not acknowledged, though from reading I can gather thousands of units (mostly the minitower psu (305w) and desktop PSU) are affected.

[lagacy]

Hi all
I have just got a used mobo Dell Optiplex 755. The mobo code is OGM819-13740 assembled in China. Two capacitors have been replaced by Nichicon 1000uF-85oC. They are C667 near internal spk socket and C502 b/w the CPU and the North bridge. I would appreciate if you could help me with the exact value of the capacitors which have been replaced.
Thank you
Lagacy

[midibob]

Hi Lagacy,

I would think if it's anything like the 620's then 85c rated caps won't last very long. Dell used 85c for the smaller valued ones and they nearly all go high ESR. The big boys, 1000uf etc will probably vent after a short while. They used to at 105c after a couple of years!!

Midibob

[PCTechNY23]

I was able to find pictures/list of the GX620 USFF caps here:

http://www.flickr.com/photos/[email protected]/4011932129/

http://www.flickr.com/photos/3082593...n/photostream/

The Cap King has the kits for $19 shipped.

[PCBONEZ]

Problem is he doesn't supply the 220uF and on GX620 those go too.

Originally Posted by midibob

Well I have to start with a loud shout of 'Geronimo' as I now have a working board.

What I've found is the 220uF caps were all going low capacitance and only being rated at 85c I'm not surprised. The ones around the outside of the board were not too bad (0.7) but the middle ones varied from ESR's of open circuit, 70, 40, 12 ohms etc. I therefore decided to replace all of them with 105c.

I replaced the two vented 820uF and out of interest they measured around 6 ohms.
All the other caps were still measuring 0.1 so for now I've decided to leave them and see how it goes. Possibly short sighted I know but checking two boards now it appears they don't suffer the same stress.

[Topcat]

Originally Posted by PCBONEZ

Problem is he doesn't supply the 220uF and on GX620 those go too.

I do have 220uF caps now, and a kit for the GX620 is coming soon, I'm starting to really see a lot of these.

http://www.badcaps.net/pages.php?vid=22

[PCBONEZ]

I was talking about 'that other guy'.

I expected GX620 to 'get popular' on the re-cap front eventually.

Maybe eventually someone will come up with a CD bay module for Optiplex with a metal tray that can be used to toast bread or bake personal pizzas.
.

[PCTechNY23]

Have you seen any 16v 220uFs go bad? It wouldn't surprise me if the ones under the hard drive do go I just haven't seen any on the 20 boards we got replaced by Dell. I did see a couple bulging 25v 22uFs.

[PCBONEZ]

Read the quote in my last post.
[Which was quoted right from this thread.]

I put it there so you wouldn't have to ask that question.

Personally I've seen them go bad on Intel boards all the way back to Socket 370.
[Not even 'built for Dell' Intel boards, any Intel board]
Usually happens when the fan and vents are clogged full of crap to the system isn't getting cooled.
I have an Intel D850GB [Retail version, P4 socket 423] and an Intel Kittyhawk [OEM'ed to Gateway, socket 370] in the shop right now.
- On both of them about 1/2 the 85c 220uF 16v are actually bloated.
.