[MagmaManiac]

Hello Forum,

Summary: Weird burning smell for 2 or 3 boots --> Doesn't turn on, no sounds or lights from comp --> replaced power supply --> worked for a few boots --> back to completely nonresponsive state 15 mins later (details follow....)

I do not know the system specs and I can't find them out without posting this issue at this time. It may not be that necessary to know the details but I can find out soon if necessary. Let's just say it is NOT a new computer - the motherboard is large - I could tell you the model in a later post - the processor is 1.x GHz, something like 512 MB RAM, I have 2 HDs. I am running Win XP.

Old Power supply: Was pretty old, up to 10 years old but maybe a few years younger (300 or 350 W). I haven't seen the computer much for 3 years since I started using and it was upgraded in the meantime.

One day I turned on my computer and shortly afterwards the room started smelling like burning metal/rubber or something acridly foul. Opened the case and nothing seemed to be boiling or noticeably hot, though I didn't really touch around. The only thing that was reasonably warm was the P/S. I thought I noticed the smell coming from it but it was only slightly smellier in that area, at most. Didn't add anything special or change anything in comp recently beforehand. Played loud music on in the night before but the speakers have their own power supply.

So I decided to replace the P/S - I purchased an hec HP485D 485W ATX12V Power Supply (says something like ORION on the actual P/S label). It is a generic brand it seems and cheap (limited budget and figured no reason to spend a lot on P/S for this comp). So I replaced the power supply and connected everything and it worked! My friend helped me connect the power supply and said it didn't really matter what I connected to which cable. The first few boots there were some error messages that the floppy drive was not recognized even though it was hooked up. The system booted once in spite of the startup message but then I would get to the blue WinXP background and freeze startup would freeze. The message disappeared after completely disconnecting (power and mboard connection) the floppy and the computer booted up and I got into Windows once or twice perfectly fine.

THEN, I tried to boot the computer again after about 15 min and it didn't budge. Since then nothing has worked. I have nothing connected but a keyboard and monitor. ABSOLUTELY NO SOUNDS OR LIGHTS following these steps:

1. Unplugging/flipping P/S switch/both + pressing down power button 5-30 secs + plugging back in

2. Unplugged + flipped voltage switch back and forth + pressing power down + plug in and turn on

3. Unplugged + drained power + repeat MBOARD power connection + try again

4. Unplugged + grounded hands + Removed memory cards + drain power + plug in --> NOTHING AT ALL

5. Replaced memory cards + unplugged both power & data connections from everything (except the power to MBOARD from P/S) + plugged in power cord --> NOTHING


The only things I haven't tried that I have read about:
1. Another power cord (this one seemed to work for those few recent boots)
2. Removing all nonessential PCI devices and reseting BIOS.

Does anyone have any ideas?

Thanks,
Michael

[lawson_jl]

It's extremely likey that when your PSU blew it damaged your mobo as well. If you have removed and replaced everything else and nothing works then it's either your mobo or cpu. In this case it's likely your mobo.

[MagmaManiac]

So it came back to life with the new P/S for those 5 or 7 boots? Or were those boots enough to put the nail in the coffin of the already damaged, half-dead MOBO?

[MagmaManiac]

I used my friend's power cord and everything works fine now.

The original power cord was working before with the new power supply for a short while so I'm not sure what happened.

It's all good in any case...