My computer is in shambles
 

The other day I came home and my desktop computer was turned off. I powered it back on and got a message on the BIOS screen that it shut off due to the CPU overheating. The computer shut off four seconds later. Sure enough, there was a ton of dust inside my computer that I neglected to clean out. I used some compressed air and got a ton of it out. I also checked to make sure all of the fans were still working (they are).

However, even after doing this, the computer would continue to display the overheat message, and then shut off four seconds later. I tried putting a huge fan next to the inside of the computer when starting up, but that had no effect. It seems to no longer be an issue of temperature.

When booting, there is a POST code of four long beeps (high, low, high, low). I read the manual for my mobo (Intel D865PERL), but it mentioned no such code. Also, now the BIOS screen doesn't even appear any more when booting. I still get the POST code though.

I asked a couple people at work and they suspect the mobo or possibly the CPU has gone bad. I think it may also possibly be a power supply issue. I have no proof of anything though. Intel's customer support won't help me here either.

What should I do to get my comp back up and running?

I'd start by disconnecting everything except for the CPU and RAM to see if you get the same error. If so I'd say it's either the PSU or CPU.

Everything has been disconnected from the PSU/mobo except the CPU, RAM, and fans. The POST is now a single short beep denoting normal startup, but it still shuts off after 4 seconds.

Well I looked up the post error codes for your motherboard (I'm assuming your system BIOS is AMI.) No idea what the continuous long beeps means. Though I'm sure it had something to do with the ventilation issue ;).

As for your shut off problem have you reseated the PSU (switch the PSU's voltage selector to 220V then back to the original setting) and the CPU itself?

Sorry I can't be of more help. All I can tell is that your motherboard is working properly at the moment (single beep = all good.) So the sudden shutoff would point to either a PSU failure or the CPU being damaged.

Weird. I wonder if the BIOS chip has gotton messed up somehow.

That would make me think it's one of the things you disconnected that was causing the problem. Perhaps try a new video card in there and see if that changes things (even an old PCI one would be fine)?

Another possibility is the PSU is deadish and can only stay on for about four seconds before shorting out, overheating, or some other sort of thing going wrong. If you have another PSU somewhere else in the house I'd recommend trying that with just the RAM plugged in and see if you can access your BIOS.

When you turn the computer on does it smell like burnt electronics at all (sniff around the back of the PSU)?

Are the capacitors on the motherboard swollen or leaking? Here is an image. Notice in the back row, the tops of the capacitors are slightly bulging instead of perfectly flat. If your motherboard has capacitors that look like this, it is time to replace the board.

http://i.n.com.com/i/ne/p/photo/capa...le_500x375.jpg

Or simply replace the caps. If the rest of the board is fine it's cheaper.

This happened to me with my 6 year old computer, I found out that my motherboard had swollen caps, and a broken RAM.

I only needed to remove the ram, but in worst case scenario, you might have to buy a new motherboard.

russ, none of the capacitors appear to be swollen. They all seem pretty flat to me. Thanks for the tip though.

Kairyu, I reseated the PSU, but when I went to reseat the CPU I realized that the thermal paste had dried out and the heatsink wasn't sticking the the CPU any more. I'm going to buy some and get that thing back on. After that, I'm going to test this out.

I cleaned off the old thermal paste with isopropyl alcohol and applied new "silver thermal compound" as directed. That didn't fix anything. I bought and installed a new, stronger power supply. Still no dice.

I'm going to check later to make sure everything is hooked up properly as it should be at this stage, but I'm now pretty positive that the problem is either the mobo or CPU (... or possibly the RAM).

Tested good RAM in my comp; still no boot. I'm tired of this. I'm just going to buy a new mobo and CPU.

New parts got here today. They did the trick. My computer works now. Only one problem: Now my video card's fan is making all kinds of weird noise. The fan is clear of obstructions, the power cable is hooked up to it correctly, and everything else seems fine, so I don't know what the deal is. Anyone here experience anything like this before? I don't know if I trust leaving my computer on while this video card is going all crazy.

The fan could be unbalanced. Is it an older card or is your machine not sitting level?

My machine is level. My card is three years old; it's a Radeon 9800. I read something somewhere about the possibility of ball bearings in the fan getting out of place. I did move the card around a lot while rebuilding my PC; perhaps it's a possibility.

I have a fan on my video card where it'll happen now and then, I usually just bang the side of my computer until it jars it into the right place. Other times I've found if I put a thin book or two under various legs of the case and tilt it a few degrees it'll help the fan slide into a happier spot where it won't resonate as badly.

OK, that sounds like a decent enough solution for my needs. I might try something along those lines. Anyway, while I haven't been doing anything graphically intensive (save Photoshop), my computer has been on for several hours across multiple sessions without problems, so I think all is well. I'm not even sure if my graphics card fan is still acting up; my other fans make so much noise that it's hard to tell. And on that note, for all I know, the card could have been this way even before my mobo/CPU broke.

Thanks for all of the help, RR. =} Things should be good for now.

There are a thousand and one guides to reseating or upgrading video card fan/cooling online anyway, you could always buy a passive or silent fan replacement for whatever cooler you have now if it just won't go away.

What are you going to do with the old mobo/cpu?

Right now the old mobo/cpu are sitting in bubble wrap inside a box in my closet. I'm holding onto this stuff for now because either the mobo or cpu may still be in working condition. If I ever have another problem like this, I'll have some spare parts to play around with.