Dell Optiplex GX280 no boot and fan going crazy

[Antoshka]

In my Dell Optiplex GX280 SFF was the same problem. I've found that PSU connector P2 was like "burned" inside (under +12VDC yellow wires). I think that high power of CPU eventually caused lost of contact in this segment. I made some adjustments to connector and now Dell boots succesfully.
Maybe it will help..

[imbo26]

you had requested if anyone has any info on reviving the optiplex gx280 to please fill you in,ok i picked up 2 of the gx280s from a local recycling yard the tower model and the smaller form factor gx280 model,neither worked both did the turbo fan thing,i have revived both units by applying a technique used in repairing xbox360s ive used countless times,one person mentioned the horrible quality of solder ur right the solder used in the assembly of these units is terrible,using the heat gun method on low setting to reball/reflow the solder joints of the boards chip set and by chipset i mean southbridge/video/nic/usb/ect,and flip the motherboard over after the top has cooled atleast 15 minutes and with the cpu heat sink and cpu itself removed u wanna reflow the bottom and make sure to pay a little extra attention to the bottom were the southbridge and cpu socket are,this method revived both gx280s this was over a year ago and one of them stays on 24hours a day 7days a week not exagerating and i play world of warcraft on it daily,quick tip u need a heatgun/paint stripper not a hair dryer hairdryers dont get hot enough,second keep the heat gun at least half a foot away(above)from the board at all times this is to keep it from accidently getting the board to hot and blowing smalll components off,and third keep the heat gun moving at all times pick a chipset and make slow constantly moving circles around it do that for 5 minutes and move to the next area example(the southbridge),wrap the plastic sockets in tin foil to avoid warping them i do this all the time with xbox360s unplug from mains power press power on and hold for 10secs to assure no remaining voltage that way u wont damage anything in case the foil shorts anything while reflowing,and lastly DONT KNOCK MOVE HIT BUMP ECT the board during or atleast 15mins after cooling we dont want anything getting knocked off ,

sorry for the bad spelling i do hope this helps some of you get ur gx280s running agian it has helped me loads of times getting laptop boards,xbox360 boards,countless desktop boards,even cell phone logic boards

[PCBONEZ]

The soldering you are talking about was the early RoHS [lead free] ball-grid problem that affected every chipset on every motherboard and it thus it is not a problem with THAT 'board' or THAT 'manufacturer' or even with motherboards, it is a problem with all electronics THAT 'age'. The problem shows up in printers, cell phone, appliances, and *anything* electronic that is THAT 'age'.
Even then it's not like 'common' for things to fail from it.
- Although it probably shares measurable percentage of the reasons for failure when something that age does fail, they aren't dropping like flies from THAT.

If you failed to remove the electrolytic caps while you did this then you 'aged' the ever lovin' snot out of the caps.
Not too bright.
.

[abebe]

i am experiencing this problems.turbo fan speed no display.and amber power light.any solution?

[severach]

Pull and reseat components. Start with the RAM, next the video card.

[enya]

im experience with high fan speed and no display... plz guide me from where to start ? which caps could be bad ? im not seeing any blown cap . plz help

[micdis]

You should also try to remove the plate that is holding the CPU in place. Install the CPU with just the fan on top. The fixing of the plate will bend the board a little bit. This sometimes causes the fan crazy thing (well i guess indirectly). You can test if this solution will work by booting up and on the same moment pushing on top of the fan.

[abebe]

what is the temperature of the heat gun?

[aurgathor]

I have a small desktop GX280 that is mostly dead. I thought it was a cap problem, but after reading this thread there's another possibility, a cracked solder under a BGA, and I don't think I can do much about that.
The caps I've seen in repair kits are 1500uF 6.3V and 1800 uF 6.3V, and there are nine of the latter next to the CPU socket.

Did anyone ever successfully repair this board (see attachment) by recapping? Which caps were replaced? How did the caps fail?

In addition to the 9 caps next to the CPU, there are 2 unused spots, presumably for the same 1800 uF cap. Can I just add 2 new caps there and leave the old ones in place? The sum of total capacity should increase by about 3600, and the ESR should go down somewhat, and if the problem is with the caps it should make a noticeable improvement.
Currently, it starts posting maybe 1 out of 10 times (but never finish booting), and about 6 out of 10 times the fan just goes crazy.

TIA

[retiredcaps]

Did you check the power supply for bad caps as well?

[aurgathor]

I did not check them with a meter, but I do not see bulging or leaking caps in the PS.

[aurgathor]

I measured (in circuit) the 1800 uF caps (9) next to the CPU socket, and depending on frequency, they're about 1550 - 1600 uF. Definitely less than 1800 but within 20%.

The 1000 uF/16V caps are about 850 uF each, also a little on the low side, but also within 20%.

Kinda hard to figure out what to do.... it's not like a 1000 uF cap measuring 125.

[JayArr_BC]

We've repaired over 50 Dell boards, 270s, 280 and 745s that have what we call "runaway fan".

The easiest test we've found is to push down on the top of the fan on the CPU heat sink, if it boots with the added pressure your problem is cracked solder balls under the 775 CPU socket.

There are all kinds of voodoo ways of trying to re-flow the solder balls, you can wrap it in a blanket, heat it with a hot air gun, put it on a pancake griddle. None of the quicky ways gives great, consistant or guaranteed results. We have an IR solder station and still only cure 9/10.
Sometimes we can re-flow the socket sometimes we have to remove it nad put a new one on.

Of course you should change all the caps before you do anything to the BGA socket, start with the easy stuff but if after all the caps have been changed the fan still takes off like crazy try booting it with some additional pressure on the CPU

Jeff

[aurgathor]

Good info, thanks. Thing is, I'd like to find out before recapping if it's the caps or cracked solder balls, so I think I'll just "spring load" the HSF first to see if that makes any difference.