Computer smells burned. Ideas?

[Micah]

Hi,

I have a server that I leave running all the time (Linux, MythTV backend, SMB, and such). It has been doing very well for the 6 months that I've had it put together. Last night, however, I got home and smelled that oh-so-familiar burnt component smell. I know it well since I've had problems with incorrectly installed heatsinks...

Anyways, it smelled bad, but the computer was still running fine. I could ssh into it without a problem. I shut it down, opened the case and looked inside. The smell was strong in the case, but I couldn't pinpoint it. I closed it back up, turned it back on, and it seemed fine.

When I got up this morning, it was off. I didn't have a chance to see if it would come back up, since I was late for work.

So, anybody got any advice on how to hunt down my problem? I don't exactly have duplicates of everything lying around to test with, so that's kind of out of the question.

Here's the system in question:
Athlon XP 1600+ (socket A, I think)
Epox 8KHA+ mobo (can't remember exact specs, just name)
512MB of RAM (mix & match)
NVidia GeForce4 Ti4200
Hauppauge PVR-250
Seagate 7200.7 300GB IDE
Maxtor 250GB IDE
Fedora Core 4


Based on the smell I would guess CPU, but I guess it could possibly be mobo as well.

Any advice would be appreciated.

 

[Maximilian]

I hate socket A, the amount of horror stories and people smelling the rig to see if its running ok rather than looking at the monitor to see a POST...

Anyways, personal opinion aside, i would check out that cpu as socket A cpu's are prone to burning out, but if you say its still working that does make me wonder what else it could possibly be as when a cpu burns out it typically wont work afterwards. Any temp readings? If you leave it on 24/7 its possible it was overheating and causing the smell.

 

[farmercal]

If you couldn't see anything on the mb, try looking at the ps.

 

[kd2777]

If I where guessing, and that is all I am doing, I would just PSU. Because I had one go out and it stunk.

kd

 

[Micah]

hmm, i'll have to check temp readings. it sits in a closet in a farily enclosed space, but has a CPU vent, decent HSF, and a 120mm fan on back. All fans are going at full speed.

Plus, it's been running fine for about 6 months.

And yes, I hate socket A as well. Long ago, I burned up a perfectly good CPU because of improper heatsink installation. I swore I'd never again buy an AMD cpu...that didn't work (luckily). Now, they are much less prone to instant frying, the cores are not exposed for easy cracking, and I don't feel as scared trying to work with them. Now, I don't even consider Intel CPUs.

 

[biostud]

another vote for PSU, specially since you haven't mentioned what brand and model it is.

 

[Micah]

Yeah, I was wondering about PSU too. It is the only thing I can think of that would be able to function after having serious problems. Luckily, I actually have a spare PSU lying around, although it's pretty low power (200W). On the other hand, this thing is fairly old and doesn't have any really beefy components in it.

 

[Micah]

Thanks for all the quick replies. I'll see about swapping out PSU when I get a chance.

 

[biostud]

Originally posted by: Micah
Thanks for all the quick replies. I'll see about swapping out PSU when I get a chance.

DO NOT TRY TO RUN YOUR RIG WITH THE 200W PSU!!!!!!!

you'll most likely fry your computer. 300W is the least.

 

[mechBgon]

What brand and model is the power supply that's been running the system?

Also, look over that old EPoX for capacitors that are leaking fluid, or bulging. I seem to recall them having gotten sold some bad capacitors during Capacitorgate

 

[Maximilian]

Originally posted by: biostud

Originally posted by: Micah
Thanks for all the quick replies. I'll see about swapping out PSU when I get a chance.

DO NOT TRY TO RUN YOUR RIG WITH THE 200W PSU!!!!!!!

you'll most likely fry your computer. 300W is the least.

Would it not just fry the PSU? Suppose if its generic it might fry the comp...

Disconnect whatever hard drive is your secondary one and remove as many non vital things you can if your gonna test with a 200w.

 

[biostud]

Originally posted by: Soviet

Originally posted by: biostud

Originally posted by: Micah
Thanks for all the quick replies. I'll see about swapping out PSU when I get a chance.

DO NOT TRY TO RUN YOUR RIG WITH THE 200W PSU!!!!!!!

you'll most likely fry your computer. 300W is the least.

Would it not just fry the PSU? Suppose if its generic it might fry the comp...

Disconnect whatever hard drive is your secondary one and remove as many non vital things you can if your gonna test with a 200w.

A friend of mine got his 4200Ti toasted because of a weak PSU.

 

[GalvanizedYankee]

Originally posted by: mechBgon
What brand and model is the power supply that's been running the system?

Also, look over that old EPoX for capacitors that are leaking fluid, or bulging. I seem to recall them having gotten sold some bad capacitors during Capacitorgate

If the burning smell is mixed with a nasty rotten egg, fart smell. Look for bad caps in the
PSU or on the mainboard.

For pics of bad caps go to http://www.motherboardrepair.com/ or http://www.badcaps.net/


...Galvanized

 

[Puffnstuff]

A weak ps will generate voltage swings that can damage everything hooked to it.

 

[Micah]

Maybe I'll see if I can borrow a PSU from work to test with. Splitting up the drives won't work, since they are in an LVM (kind of like a sofware RAID).

Thanks again for the ideas and warnings.

 

[mechBgon]

*forms megaphone out of rolled-up pizza box*

WHAT

BRAND

AND

MODEL

OF

POWER SUPPLYYYYYYYY


Answering peoples' questions is part of the troubleshooting thing here

 

[Micah]

Sorry about the delay, I just got home.

The PSU is a Skyhawk Power One, with max output power of 385-425W.

However!!! I don't think the PSU is the problem. Based on the advice to look for bad capacitors, I got out the flashlight and went looking, here's what I saw:
http://www.wedemeyers.net/wordpress/wp-...img/micah/bad_capacitors/bad_cap_1.jpg
http://www.wedemeyers.net/wordpress/wp-...img/micah/bad_capacitors/bad_cap_2.jpg

Notice the brown spots on top of the capacitors. They have been there for a long time, and I have wondered about them before, but since it worked I said "oh well, forget it." I guess that maybe I should look at getting a new motherboard

I hate "upgrading" motherboards. It is basically an entire system re-build, and it often requires total reinstall of OS and software. Maybe Linux will be less picky, but who knows. Besides, for this system, I don't want to upgrade. I want it to just work. It's not like a storage server needs all the hot mobo features anyways

OK, enough whining. Off to the FS/FT forum to see if I can find a cheap socket-A mobo that is Linux friendly...

 

[mechBgon]

Ahh, yep, you found your problem Good hunting!

 

[imported_Baloo]

You are not going to fry a computer by underpowering it. A 200 watt power supply is probably more than adequate. The worst that could happen is you fry the PSU. No big loss there. Sometimes additional damage occurs, but I have only seen that on overcolcked systems, and in those case, it wasn't really the PSU that failed, just that the PSU was damaged as well/ I've run systems more power hungry than yours with 145 Watt microATX power supplies with never a problem. It's not like you running a P4 3GHZ overclocked to 3.7 with two $500 Video cards and several 15K SCSI or 10K Raptor drives. It's the quality of the power supply, not the wattage. Going for more watts is a poor substitute for quality. Not that you are, just sharing that.

I'd bet if you opened up your existing PSU, you'd find something burnt inside.

 

[Maximilian]

Originally posted by: Baloo
You are not going to fry a computer by underpowering it. A 200 watt power supply is probably more than adequate. The worst that could happen is you fry the PSU. No big loss there. Sometimes additional damage occurs, but I have only seen that on overcolcked systems, and in those case, it wasn't really the PSU that failed, just that the PSU was damaged as well/ I've run systems more power hungry than yours with 145 Watt microATX power supplies with never a problem. It's not like you running a P4 3GHZ overclocked to 3.7 with two $500 Video cards and several 15K SCSI or 10K Raptor drives. It's the quality of the power supply, not the wattage. Going for more watts is a poor substitute for quality. Not that you are, just sharing that.

I'd bet if you opened up your existing PSU, you'd find something burnt inside.

Look at the pics with the brown leaky stuff above.

 

[Zepper]

Bad caps create shorts across the PSU which SHOULD be trapped by the PSUs current limiters... Apparently yours weren't. Your mobo is well known for having bad caps. Most of the mobo mfr's that have cap problem will fix them regardless of warranty status. But you'll probably have to be persistent. Get the caps fixed BEFORE trying a new PSU. Don't need to chance taking that out too. There are places to buy sets of caps for doing the replacement yourself, but that's NOT a ton of fun...

.bh.

 

[Micah]

And the culprit is...the PSU!!

I replaced the mobo and it still didn't work. This time, though, the fans did start spinning at least. However about 30 secs after I started it up, I started smelling the burned smell again. Since I had the case open, I went smelling.

CPU - no bad smell (whew!)
other components - no smell
rear exhaust from PSU - awful smell, like you can't believe.

So, I went to BB, bought a new Antect 350W PSU, popped it in, and it worked like a charm. As a bonus, Linux was able to totally reconfigure to utilize the new motherboard as well. It booted up like a dream and didn't complain a bit.

Thanks to all for your suggestions and help!

 

[CrispyFried]

may be that the shorted caps took the old psu out. glad all is well again.

 

[Micah]

I should have posted some pictures of inside of PSU. I opened it up and saw scorch marks inside. The PCB (I think) was white, so the brown scorch marks were very easy to see.

That's what I get with a piece of junk PSU that came with a crappy bargain case. Works for 4 months then craps out.

 

[RebateMonger]

n.m.