Dell OptiPlex GX270 - multiple bad cap failures

[scarfman]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Here's something both interesting and annoying. I just found another board that has a cap that is bulging at the top and also at the bottom. Dell refuses to replace it because the board is not showing symptoms of failure. So now I have to monitor the system here in my office until it does show some kind of symptom or starts leaking.

Is this BS or what?

[PeteS in CA]

Re: Dell OptiPlex GX270 - multiple bad cap failures

You could be looking at a cooling issue - the airflow in that area may be inadequate, and the Rubies are getting cooked. And if the over-filling with electrolyte story re the Nichicon HNs and HMs is true, the "aqueous" electrolyte expands with heat, which certainly is present.

[scarfman]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Does anyone know what that single capacitor between the RAM & AGP slot regulates power for? For example, if it's for the RAM then I can run memory diagnostics to see if it's affecting memory performance.

Any feedback would be appreciated.

[willawake]

Re: Dell OptiPlex GX270 - multiple bad cap failures

measure the volts across it, maybe it will give indication.

[MD Willington]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Spotted one at work just 5 minutes ago, GX270, bad caps near the AGP port.. was chatting with the guy who was putting in a new AGP card, the card looks great, A Gigabyte card with Ruby's.... they are fine, installed another card and the problem persisted... I saw the GX270 on the front, and asked if we could open it up.. I looked straight at the AGP slot...

Nichicon ready to pop, looked at a few others, same deal...

MD

[scarfman]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Spotted one at work just 5 minutes ago, GX270, bad caps near the AGP port.. was chatting with the guy who was putting in a new AGP card, the card looks great, A Gigabyte card with Ruby's.... they are fine, installed another card and the problem persisted... I saw the GX270 on the front, and asked if we could open it up.. I looked straight at the AGP slot...

Nichicon ready to pop, looked at a few others, same deal...

MD

You mentioned "the problem persisted". What was the problem he was having? Maybe that will help identify what this cap does.

[MD Willington]

Re: Dell OptiPlex GX270 - multiple bad cap failures

He never identified the problem other than he removed a good video card and replaced it with a new good video card and there was still a problem.

[sean5302]

Re: Dell OptiPlex GX270 - multiple bad cap failures

My Optiplex GX270 has just died.
It's been acting strangely for the past 2 weeks. I live in England and the weather is warm, high summer, actually.
The pc fan was screaming, then the pc would turn off. Restarting would give no video output but the cd rom drive led would flash 4 times.
I opened the case and many Nichicon capacitors are heavily bulged.

After an hour on the phone to Dell, they refuse to help as I am a second owner. I bought the pc from a computer shop when it was 3 months old. I've had it for 1 year. Dell say they owe me nothing.
I find that hard to stomach. Surely it's their manufacturing fault. This would have happened regardless of first or second ownership.
Dell don't want to know.
Their parts section has offered a replacement motherboard for £110 ie $200 but will only warrant it for 3 months as they have rebuilt it.
Can't I do anything else, please?

[sean5302]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Assuming that I'll get nowhere with Dell my options seem to be:
1. Find a replacement board. Ebay or suchlike. Maybe hard to do as these boards are in short supply, and a vendor may sell a broken one
2.Take a hacksaw to the case and fit a non-Dell board.
3. Replace the caps. There seems to be 23 and 5 are very bulged. Should I just change the bulged ones? Will any cap do as a replacement, as long as the voltage and capacitance are at least what is listed on the old ones?

I have to say I'll never buy a Dell again. I'm aware that other makers had bad caps, but Dell doesn't seem to look after customers as well.

[Per Hansson]

Re: Dell OptiPlex GX270 - multiple bad cap failures

You need to use Low (or preferably Ultra Low) ESR capacitors, Only Nichicon HM or HN capacitors will need to be replaced, the rest should be high quality, this issue was that Nichicon had a bad batch of capacitors, which only affected these models...

You can also send it in to Topcat, the owner of these boards... Look at the mainpage of www.badcaps.net

I would not recommend you to buy a used board, because it will most likley have capacitors from the same Nichicon bad batch snafu...

"Where can I buy replacement capacitors"
https://www.badcaps.net/forum/showthread.php?t=613

"The GOOD Capacitors Thread!!"
https://www.badcaps.net/forum/showthread.php?t=414

[sean5302]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Thanks very much.
Replacement caps seem to be cheap enough.
I just hope that it's only the caps that have failed and not some other parts too.
We'll see. I'll let people know my results, hopefully next week.

[sean5302]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Well, I removed the 5 obviously bulging Nichicon caps.

Not an easy job. Easy to melt the solder and remove the old cap but the hole on the board was still blocked with solder.

Spent ages, got it clean.

I then tested the old caps with a large battery. They held their charge when tested with my meter, so maybe they weren't the fault.

I bought 5 replacements for only £4 ($7) and fitted them easily. No good.

I'm thinking of ditching the mobo and buying something new.

Anyone recommend a good mobo? Needs to be Pentium 4 socket 478 and DDR333 RAM compatible.

I'll never buy another Dell as long as I live.

[willawake]

Re: Dell OptiPlex GX270 - multiple bad cap failures

does it have exactly the same problem now as before?

i dont like the "spent ages" to clean the holes, long heating is not recommended as it can damage the lead port or nearby traces.

what caps did you use anyway?

I then tested the old caps with a large battery. They held their charge when tested with my meter, so maybe they weren't the fault.

you need to read more about the failure modes of caps

[Mayoo]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Sorry if there is an answer for my question. SO basically i planned to removed all the 13 Nichon Caps in the row next to CPU in GX270 Mobo. Will that fix the problem or is there any where else i have to change the caps in my mobo ?

[scarfman]

Re: Dell OptiPlex GX270 - multiple bad cap failures

The ones that are also subject for failure are the three 1800uf caps directly behind the parallel ports (they're the ones I've seen the most failures of), the three 1500uf caps: one inbetween the RAM slots and the AGP slot and the other two inbetween the RAM slots and the CPU socket, and the two 1800uf caps right next to the ATX power connector.

[MD Willington]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Drag up a dead thread here...

Today found another one, one of the SW tools guys said his machine was acting weird... bloated Nichicon...

Two weeks back I found two others in the same day...

[swan9999]

Re: Dell OptiPlex GX270 - multiple bad cap failures

Hi Everybody, I'm a “New Guy” to this place and have read the postings and wanted to contribute to what I hope will be of some help to at least some of this community. First off this will not help much for the big dell clients so they may want to skip this posting and save their time. My thoughts are directed to the little guy, like me, that has one or maybe two of these computers and wants to do his own repair work. It is here that I hope to offer some ideas and suggestions to the non-electronics tech types. There is a Brit here that was talking about his problems in soldering and especially desoldering. I feel for him and have some ideas that may help. Any beginner may see some problems in tron work; it is a skill, just like riding a bike. Nobody is born knowing this stuff. You get better with practice. There are some tried and true methods that may make the learning curve both faster as well as more painless. As I see things, for us little guys the main motive in doing our own work is, as in my case, is to save money.
To qualify myself to you let me say this: I'm a retired avionics tech that spent a career in the US Navy working on just these kinds of problems (component remove and replacement as well as circuit card repair)…. And to you other pros out there, by all means check my suggestions and kibbitz as necessary, especially if you think I'm passing out “bad gouge”. So Here goes.

Soldering and desoldering 101:

1 Assemble some basic supplies: solder (rosin core 60/40 is what I use), alcohol (100% no water), an eraser, liquid flux in a dispenser bottle, an acid brush for cleaning (that's the nomenclature of the brush… no we don't use acid!), a moist rag (for soldering pencil tip cleaning), soldering pencil (15 or 20 watt rating should be fine, if you are careful and quick a 30watt works well but you can get into trouble faster (with too much heat), a soldering pencil holder (not absolutely necessary but handy, and a roll or two of desoldering wick.
Soldering:
 Clean the leads and the pads on the card with alcohol, using the brush and or dry rag or with the eraser.
 Tin the tip of the soldering pencil: (wipe it off, flux it, apply a bit of solder, and make sure that the tip is “wetted”. It should be bright and shine like chrome.
 Tin the leads of the component. Don't leave too much solder on them…tinning is just a very thin coating of solder, nothing more. Note: If you can't get the lead in the hole in the card you left too much solder on it…warm the lead back up with the pencil and wipe it off. And reapply a thin film of flux on the lead before insertion in card.
 Place component in card and trim leads. Apply a very small amount of flux to pad on the solder side of card. With a clean tip (tin again if necessary) and a drop of flux on it (yes, it will smoke a bit, don't breath it) touch tip to pad and lead. The solder should flow like water. If it does not things are not clean and fluxed. Go back and clean and then flux as described.
 Get out the acid brush and gently scrub the repaired area with alcohol and blot. Do it again until the area is no longer sticky with flux.
 You are done!
Desoldering:
 Tin the soldering pencil and using the acid brush and/ or the eraser clean the card in the area of repair
 Apply a small amount of flux to pad and lead (on the solder side of card).
 Apply a drop or two of flux to the wick.
 Set the wick on the pad and then touch the tip of your well-tinned and clean soldering pencil to the wick. The solder should flow almost immediately and be sucked up into the wick. Remove the wick and tip at the same time from the pad. Cut the used portion of wick off and discard. Note: This step is where you must be careful because if you leave the tip on the pad for too long you can heat damage the pad…lift it right off the card! Don't do that.
 Evaluate the solder removal. The component must come off 1st. Once that is done you want to clean up the pads and the holes. Sometimes the pad comes clean but the holes are still plugged with old solder. Here is the fix. Apply a small drop of solder to your well-tinned and cleaned tip. Fill the holes up with this new solder. Now, with no component lead in your way and fresh solder (yes, it does get old…with too much reheating and reflowing) in the holes and on the pads go back an try the standard desoldering method described above again. This works for two reasons. First, fresh solder flows better, and two, by filling the hole heat is conducted throughout the area more evenly thereby liquefying the solder more completely and facilitating removal (by capillary action in the wick)
 Clean up your mess. Get out the acid brush, alcohol, and rags. Note: I use toilet paper or Kleenex instead of rags for this cleaning up step…throw aways, right.
 You are done!

2 Get a dead circuit card from your favorite computer repair tech. And practice a bit. This way if you screw up you haven't made a mess of your computer.
3 Other Thoughts
 Remove and replace just one component at a time.
 Pay attention to where the soldering pencil is…situational awareness! Are you leaning the barrel of the pencil against another component….and cooking it! Hope not.
 Clean is good. Cleaner is better.
 Practice, Practice, Practice


I hope that this helps the do it yourselfers.

As Porky Pig says at the end of the cartoon,
Well, that's all folks.

[kc8adu]

Re: Dell OptiPlex GX270 - multiple bad cap failures

you may need up to a 75w iron on these 6 layer motherboards.
i occasionaly have to preheat with a heatgun on low to desolder.
those huge power and ground planes soak up the heat very well.

[japlytic]

Re: Dell OptiPlex GX270 - multiple bad cap failures

you may need up to a 75w iron on these 6 layer motherboards.
i occasionaly have to preheat with a heatgun on low to desolder.
those huge power and ground planes soak up the heat very well.

I think a desoldering gun would work just fine.

[icemanr]

Re: Dell OptiPlex GX270 - multiple bad cap failures

I Have bunch of these gx270 optiplex dell computers i got at auction.All were defective, most have cap problems.I replaced the 1800uf 6.3v with 2200 6.3v,1800uf 16v with 2200uf 16v, and 1500uf 6.3v with 2200uf 6.3v and now they post.However about 1/3 of the units after burn in for day or two give thermal shutdown error and shutdown.There is some 820uf 6.3 and 680uf 10v that i didnt replace becuase they didnt look bad.Can these need replaced also.Does anyone know which caps give this perticular problem?

There is also some other smaller ones like 220uf 16v,150 6.3v

Anyone familar with this board?