earlier this morning my computer shut off and the buisy light was solid and the light on my cd-rw was on. i turned it off and then 2 hours later i turned it back on again. everything seemed fine, but i just got back in my room, after it was on for about 3 more hours, and it was shut off with those specific lights on again. i just tried restarting it, and nothing will go through to the monitor, no bios, nothing... it will just stop with those lights on. all of my fans are working fine, and my processor was not hot at all. im running slackware 9 and have p4 2ghz with a via p4x-266a. the whole thing is connected to a surge protector. no surges/power outages around here ever. i have an achieve (sp?) 500w power supply. running 2 hard drives 60 and 120gb... anyone please help, im a computer science major and need this to be fixed soon. thanks

Does the machine give any beep codes (from the speaker)? If so which ones?

Check to see if the motherboard power connector has come loose?

Any collisions / signs of failure / new devices / kernel rebuild / aggressive BIOS settings / anything else that might cause a glitch?

Strip out everything from the motherboard except the graphics card, cpu and RAM (if you've two or more sticks of RAM, leave only one in), disconnect the hard drives and then try booting.

If that doesn't work, try swapping out the power supply ( if you have a spare / friend has one).

If you can get it to POST, replace devices one at a time (leave hard drives unplugged), rebooting several times before you move onto the next device.

When you've got everything plugged in except the harddrives (and it still POSTS ok) try booting from Knoppix / boot floppy / similar (i.e. don't use the hard drives) and see if it detects hardware ok / gets to a command prompt.

Post to let us now how you get on.

well.. i pretty much unplugged everything and now it booted ok. before it would give one beep, like it was starting up, but the monitor light would still flash meaning there is nohting being sent to it.
no collisions, no signs of failure, no new devices, no rebuild, no aggressive bios, nothing that would really cause that to happen. do you think that i should leave it and see if it happens again, or should i try what you suggested still?

your call really - I'd back up my disks at the very least (before they get any more abuse).
If you've got the time, check out your hardware - put a few pieces in at a time and let it run unattended for a few hours. It might be a random thing that doesn't happen again, but a check might save you a few $currency / headaches in the future.

Just had a thought, you haven't enabled anything that would cause your drives to power down have you? Powersaving mode or similar? I remember that it doesn't always work well on nix.

One of my machines used to overheat in winter because it sat over the central heating pipes running through the floor.

well, it was running for about 20-30 minutes and it happened again, but this time it rebooted. i shut it off for now. when i get some time im going do what you suggested in your last post. you think i should plug in 1 or 2 things at a time and then leave it on for an hour or so? wow, this is frustrating... is there anything else i can do to try to troubleshoot this? specifically, how can i see if my processor is overheating? because the fan on the processor has a very slight pulsing noise...

i had the mem, and video card plugged in, thats it... i let it stand and when i came back, i turned on the monitor, and the computer has shut off... nothing was being sent to the monitor. all the fans were on, and it seemed that the compuer was running, but nothing to be seen on the monitor. in contrast to last time, the lights werent on

Are you saying that you can't see anything on your monitor? How's your video card, or do you have embedded video? Otherwise, this sounds like an overheating problem is causing your system to go down.
Also, some systems were sold on the open market where the mother board makers were using cheap capacitors. After a while, those caps started breaking down, and shorting out the system. Hope that you don't have one of those systems. Oh if you have embedded video, you can disable it in your BIOS and borrow someone's video card. If you get a normal picture on your screen then you have a bad embedded video chip.

As far as the processor temperature sensor; it is dependant on the motherboard. As is the support for the specific chip on the motherboard which reports the temperature of the cpu and the fan speed. Linux has sensor support, but I don't know whether it supports it for all motherboards. You can set the software to shut the machine down at a specified temperature, and give warnings if it reaches a non-critical but really cooking temperature setting.

Boot it up to the bios, if the MB has temp. sensors you will find a screen in the bios which will tell you temperature and fan speed.

Frankly, I would see if a shop somewhere has a bench video card you can test your system with. I had a hinky video card that caused those problems and others. That is the only video card that I have ever had fail, so even though I have worked on a lot of boxes, I really don't have that much experience with a bad video adapter card.

In my time on the bench, I personally only dealt with one dead power supply. It was already dead. I have no experience with a "sick" one. So I don't know the symptoms.

If you aren't familiar and haven't done it often, I would let someone else replace your cpu fan. Nice thing about P-4s they will shut down instead of fry.
I am a paranoid about chip cooling fans, if it sounds the least bit "funny" it goes.

I have worked on computers which had over-heating problems. They can do really strange things. One heat-sink I took off still had the plastic over the heat-conductive paste--Gee Whiz, I wonder why it was over-heating?

Another thing I have run into was poor ventilation in some pc-cases. The case simply was not designed with the faster hard drives in mind. Those are fun, the first time you run into one. You can have all sorts of bizarre results, and all of the parts test good. But there was file corruption and other things going on. I had to change to round cables and very carefully route everything so as to keep the air-flow clean, I then had to modify the case (aluminum tape) to that I could direct airflow though the drive bay as well as a stream of cool air to move across the main board, video, ram, and processor. And, of course add two fans to move the air. The power supply air was already diverted out the back of the case. I broke the centers out of two old dead fans to use them as duct/spacers to add efficiency to the case-fans and make the thing quiet. I also built an air-box to act as the fan-mount for the processor heat-sink--because the damn thing sounded like a vacuum-cleaner. It has never needed work since.

I had the exact same thing happen to me when I got my laptop. It did it like 3 or 4 times, and then one day, I come back from class, and all the lights are off. I push the button to turn it on, and nothing happened. The processor had overheated and melted down, and fried the motherboard to a crisp in the process. Needless to say I got a new laptop. The problem with that one was that the heat conductive paste was never in contact with the processor.

Notebooks are sweet! But you MUST watch the HEAT issue!! think about it! I hear my sweet fan whirring. Then I go to an Apple store and run MY Mac in a sweet book little more then 4-5 of my cell phones set side to side on the table! Where's the fan?? Gotta cool the sweet notebook!

well, i dont have a notebook, but i went to best buy and baught a new power supply, and have had no problems since... i think im going to send my power supply in to get fixed..

Wow I had similar problems, 2 out of 3 Dell pcs went bad (after the warranty).

The first one: The motherboard and memory went dead (over heat?) everything else worked including the CPU (tested on another system) .

The second one: The power supply burnt out and the motherboard fried.

The third PC (non-Dell) that I have, suddenly just made a long beep non stop and wouldn't turn on, and I was just using it (had to reboot). Turned out to be that two of the memory slots were bad, now it "works" with only a 32MB stick but it locks up alot.

Finally, the PC that i'm using right now was locking up too much. I have to keep the case open, the 30GIG Maxtor drive that I got (Model 6E030L0), seems to heat up so bad that if you touch it you will need you go to burn unit in the emergency room (yes it's THAT hot).

Well, that's my story. What I learned was:

1. Make backups;
2. Keep the PCs cool at all times;
3. Use an UPS;
4. Use a high rated power strip that has a fuse;
5. Even "name brand" companies use "low-grade" components (specially the power supply) ;
6. build your own PC and spend $$ on high quality parts (not high-end, just high-quality);
7. have the wires in your house tested.
8. umm... I know I forgot something?