Dell Optiplex GX280 no boot and fan going crazy

[playman]

My dell is giving me some &#$%# and wont boot.
when I got it it had a PSU that was 20 pins and the motherboard is 24 pins.
So I put in a coolermaster 450w PSU and tested it with no HDD's CD's etc.
It booted and was looking allright, then I had to mod the back case alittle, to be able to fit the new PSU.
Then I inserted a DVD and HDD plugged all cables and such, then closed the lid.
Now, when I plugged it in the CPU fan went crazy, started at 110% speed, and no boot.
And if I unplugged the 4pin the fan just spinned gegntly and did not turn off, and no boot either.

I've looked around the net, and found only that a Capacitors might be problem,
altough I looked at them and did notice any leak or bulge, I did not remove the board for closer inspection.

so any one have any ideas?

[Gabriel]

Re: Dell Optiplex GX280 no boot and fan going crazy

I had the same problem with my 280 - I changed the cpu for a 630 and got no boot and the cpu fan went crazy.
I took the cpu out again and put it back in and everything was ok - maybe bad contact in the 775 socket.

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

I had the same problem with my 280 - I changed the cpu for a 630 and got no boot and the cpu fan went crazy.
I took the cpu out again and put it back in and everything was ok - maybe bad contact in the 775 socket.

Hmm, well I never "touched" the heatsink or the CPU, but I might as well take it
out and reinstall it and ad new paste, just to be sure.

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

I re-installed the CPU with new paste, plugged it in, and it worked just fine.
so I shut it down and replugged everything again, started it up and %&$ it started to behave like before, no boot and fan speed at max.

[Topcat]

Re: Dell Optiplex GX280 no boot and fan going crazy

That is known as the GX280 "turbo fan syndrome". There is no known cure for it. I've sent hundreds of these boards to the recycler over this. I've read this is caused by the BGA breaking loose under the northbridge (thank the tree huggers and RoHS compliant solder). This can not be repaired, atleast not in any manner thats economically feasible. The GX280 was a piece of crap all the way around, the only Dell board I've encountered the last decade that a simple recapping wouldn't fix.

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

Damn, and I was going to use it for a server, since it had a ok cpu and nice heat sink.

[severach]

Re: Dell Optiplex GX280 no boot and fan going crazy

GX280 turbo fan syndrome on a normally working system is often caused by the PCIe VGA card pulling out just a bit. Reseat it.

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

GX280 turbo fan syndrome on a normally working system is often caused by the PCIe VGA card pulling out just a bit. Reseat it.

No cards are currently installed, I use the onboard VGA.

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

Heh the strangest thing, I just noticed that after a night being unplugged it starts normal again, I noticed that also yester day after only about 1hour unplugged.
could that mean anything?

[PCBONEZ]

Re: Dell Optiplex GX280 no boot and fan going crazy

Does the board have 85C 4 & 5 mm caps?

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

Does the board have 85C 4 & 5 mm caps?

I'm sorry, i'm quite new at this.
how would they look like?

[PCBONEZ]

Re: Dell Optiplex GX280 no boot and fan going crazy

They look like 4 or 5 mm diameter capacitors and have 85°C written somewhere on the side.
.

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

They look like 4 or 5 mm diameter capacitors and have 85°C written somewhere on the side.
.

Ofcourse, it was to easy that I didint think of that hehe.

any way, I've found 7 85°C caps and marked them onto a new picture of the board.
The rest of the caps are 105°C

Is there any special reason why you asked about the 85's and not 105's?
what is the difference?


On the otherhand, I noticed that when i'm able to boot the PC I can get into
BIOS with out a problem, altough if I do nothing for few min it frezes and I cant do anything.
I'm not sure if it's the USB keyboard that frezes or the PC, it does not support
PS/2 connections BTW.
I was able to boot it from a Ubuntu USB key, but when I went for a smoke it was frosen again on a error, wich was ubuntu specific.

[PCBONEZ]

Re: Dell Optiplex GX280 no boot and fan going crazy

85°C caps last 25% as long as 105°C caps with the same lifetime rating because the rating is based on max temp.
There is more to it than that but that's what it all amounts to.
-
Very few people even check the 4 & 5 mm because there's an old wive's tales that they never fail.
The DO fail and cause problems, just not so often as larger caps.

Intel uses 85°C now and then and them failing after 4 or 5 years isn't unusual.
[The more heat they get the sooner they fail.]
When they go they louse up signals to the chipset and other IC's and the result is an unstable board and it's totally conceivable they could prevent boot by lousing up signals to-from the chipset necessary to boot.

It's not an Intel exclusive problem but it is fairly common on Intel & Foxconn made boards from socket 370-up.
[Intel outsources some mobo building to Foxconn.]

It could easily be confused with being a bad chipset or BGA issues but I've never heard of RoHS BGA issues on any Intel/Foxconn board with an Intel chipset [Dell or not].

I'm sure a lot of boards that could be fixed for like $1.50 in small caps get scrapped because people don't even check the small caps.
.

[Topcat]

Re: Dell Optiplex GX280 no boot and fan going crazy

^
Sorry to burst your bubble, but I've already tried that on some for a corporate client. I only wish it was something that simple. They were willing to pay just about anything to recover these boards, so trust me, I was trying and grasping at anything!! I recapped them fully, including the little ones (many of which were 85* lytics). It did not fix a single one of them, and I tried it on over 20 of them. Huge waste of time and caps. Like I said, I can't guarantee that the issue is a BGA/RoHS problem, but on that note, nobody has offered up any other solutions or causes...and believe me I looked!! I have a box full of these left if you want to take a crack at some. It's only on the GX280 boards that this problem exists, the SX280 (which is basically the same board in USFF) didn't have this problem, and they too used a lot of the 85* caps in 220uF 16v around the NB chip. I'm sure it's probably 10 cents worth of something that's killing these boards......but anyone care to enlighten us as to what it is?!

[PCBONEZ]

Re: Dell Optiplex GX280 no boot and fan going crazy

I have a whole box of bad GX280 boards, the thing is they all have -visibly- damaged southbridges. [Shinny/melted spots] They used several different PSUs in those things and my suspicion is that at least one of those PSUs had some issue with it that fries the chipsets. I never see what PSU they had attached, just the board. I imagine if you pulled the heatsink and cleaned the northbridge off some of your mystery failures you would see at least some melted northbridges.

Bad 85C caps has been an issue on Intel boards at least from i815 thru i945 chipsets and probably longer. I've actually posted photos of bloated 4 & 5 mm 85C on several vintages of Intel boards in the forum before. There's also a long discussion about bad 85C on GX620 boards. I actually have Intel socket 370, 423, & 775 boards with bloated 85C in my shop right now and non were from Dell mini-pizza ovens, they are standard ATX/uATX. In fact only one is an OEM board and it isn't for a Dell.

All the SX280's I've seen had 105C caps for the small ones.
Granted you see more than I do, but then again, I actually check that.

You can choose not to believe it if you want but 4 & 5 mm 85C caps are a definite issue on mobos, especially mobos over 4 or 5 years old. Even the slightest hint of bloating on one is a sure indicator several are shot and the board will likely be unstable if you don't replace them.

I've also corrected the 'only boots sometimes' issue several times by replacing 4 & 5 mm 85C caps that weren't visibly bloated on boards where the 6mm and up were good caps.
So, there are cases where a board's only issue is bad small 85C caps.
.

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

So I should try to replace those 85° caps and keep fingers crossed?
would it make any matter if I would use 105° caps instead of the 85°

And those 85°'s, could they be the culprit of my PC freezing up?
i'll check again later on if it's USB controller that's freezing or the whole PC.

[PCBONEZ]

Re: Dell Optiplex GX280 no boot and fan going crazy

It seems you've just changed your symptoms from 'no boot' to 'freezing up' so exactly what are the symptoms?

Yes 85C can cause problems, no it's always the problem when 85C caps are present.
- I would give replacing them a shot.
- TC would skip them and trash & replace the board.
We both know what we are doing but TC runs a repair service so he generally has clients want their boards back ASAP and I generally buy-fix-resell so I own most boards I rework outright and no one is breathing down my neck about where their board is,,, hence our priorities are different,, particularly when it comes to problem boards that may take a lot of time to figure out.

Never use 85C caps for replacements.
The 105C last much longer and don't cost significantly [if any] different.
Use an 'entry level' low ESR caps to replace the 85C.
Something like LXZ, FC, PW or similar grade.
.
.
Where did USB problems come from?
I've seen damaged and/or shorted USB ports keep a system from running by shorting the +5v rail.
.

[severach]

Dell Lite-On Power Supply Intermittent Failures

The North bridge and South bridge chips use 3.3v for I/O. I only saw 3.3v drifting low. Perhaps it could drift high just long enough to damage chips before being caught by the supply's power quality monitor circuit, especially if you repower the system many times trying to get it to run.

Tested and written Aug 2010:

I have 5 of these PS-5251-2DF2 250W supplies all with the same problem. The 3.3v lines shows LL in the LCD power supply tester. A visual check never shows any bulged capacitors. It seems odd that all would have the same failure and no visible damage. With so many I thought there might be a way to fix these with some part swapping. The 3.3v circuit is quite small so I went through it. What appeared to be a short was a 30 ohm resistor near the output. Capacitors test fine. I swapped the double diode with no improvement. The pi inductor shouldn't be a problem. Cleaning flux from the board helped. The only two parts that seemed to have some effect were the transformer and the high standing toroid between the heat sinks. Shorting this toroid causes the power supply to shut down so it is important. Leaving it out allows the supply to function with LL for the 3.3v output. Unfortunately I don't have any working supplies so swapping parts that can't be independently tested are inconclusive.

Over time it appears that the Lite-on supply gains a soft fault due to a manufacturing defect. I suspect the insulation on the transformer windings gets weak. Part of the time it works and part of the time the 3.3 volt supply is low, a condition the power supply does not detect as a fault. The GX280 motherboard does and shuts down with a flashing power led yellow orange amber when the 3.3v rail goes out of spec. The drift is not affected by removing power so the defect seems physical. Normal part swap testing is ineffective since the 3.3v line drifts in and out of spec leading to times when it works and times when it doesn't. If a Lite-on supply ever fails on the 3.3v line it should be discarded with no further testing.

GX270 Tower and SFF Lite-on supplies seem to be affected the same way. When functional the power good is often 100ms instead of the usual 240ms and if deployed these fast power good supplies fail quickly. Testing is easy. Run the supply for a long time. If the computer shuts down with a flashing orange power LED and the computer doesn't have any of the other usual problems, replace the supply.

Lite-On supply failures are unpredictable and intermittent. When in doubt, throw it out, especially for systems where downtime is money! The GX270 and GX280 don't need an unreliable and hard to troubleshoot power supply to add to their problems so it may be best to avoid Lite-On supplies altogether. Use the HiPro or Newton supplies which are more reliable and have failures that are easier to manage. Since failing Lite-on supplies can test good if tested often enough sellers may be unaware that the Lite-On supply they are selling is faulty. Unfortunately most of what sells for spare parts are these Lite-on supplies.

[playman]

Re: Dell Optiplex GX280 no boot and fan going crazy

It seems you've just changed your symptoms from 'no boot' to 'freezing up' so exactly what are the symptoms?

From what I wrote earlyer.

On the otherhand, I noticed that when i'm able to boot the PC I can get into
BIOS with out a problem, altough if I do nothing for few min it frezes and I cant do anything.
I'm not sure if it's the USB keyboard that frezes or the PC, it does not support
PS/2 connections BTW.
I was able to boot it from a Ubuntu USB key, but when I went for a smoke it was frosen again on a error, wich was ubuntu specific.

I was able to get it to post if I let it "cool" down, and get into BIOS and doing other stuff.
Altough now, I cant seem to get it posted again.
( cooled down, I mean it's like it drained electricity)

So actually I experiencing No boot with super fan and USB problems (I belive)
I havent been able to bot it up to check out if the USB freezes or if it's the PC that freezes.

Where did USB problems come from?
I've seen damaged and/or shorted USB ports keep a system from running by shorting the +5v rail.
.

I have no idea, all I know is that it was given to me becouse it was faulty, and atleast to my knowledge the USB has not sustain any damage from my behalf.


Lol I hope you understand me