As with most stories, mine needs a small introduction.

About 6 months ago I had just started to burn a cd when the power went out. The outage caused some very severe XP issues and I eventually had to do a format and reinstall.
Also about that time, I started seeing some strange behavior from the computer during start up.
I want to make it clear that I am only speculating that the power outage caused this behavior, I can't definately say that the power outage was the start of it (due to the fact that the software was so screwed up, if it was locking because of hardware, I couldn't seperate those locks from the software), but I am resonably sure it was. Ok, back to the story.
The strange behavior during startup was almost as if the computer had to warm up before it would work. If I turned it on after it had sat for a long time, say over night, it would generally boot until the windows splash screen, but lock up there. If I reset it might get farther and lock or it might start up all the way. The 2nd or 3rd time might make it all the way to windows, but lock after a couple minutes. Generally It would lock off the cold start but by the 2nd, 3rd, or 4th reset it would make it all the way up and be fine until the next time I turned it off for an extended period. When it locked, the monitor would continue to show the same thing I had been viewing and the keyboard lights would not react. ctrl + alt + delete had no effect. Only a restart affected it.

I had these symptoms for months, and I mostly ignored them because I figured it was working and I wasn't really sure what it could be, so I let it go.

Fast forward to a month ago. About this time the computer started locking during normal use, meaning not during start up. Before, once I got it past the initial lock ups it could be on for weeks at a time with no problem. A month ago, it started locking up randomly, with no obvious cause. I tried to replicate the lock ups and was unable. It would lock about once every 3-5 days, and one restart was all it needed to fix it. Then about a week ago, it started locking up more frequently, about every other hour. At this point, a restart was all it needed. Then, a day ago, it was locking every 20 minutes. After about 4 lock ups and restarts, it did not post (no beeps) on the restart. At that point, I figured it was done and I let it be.

Since then I have experimented and discovered this:

If I let it sit for a couple hours, on my first cold start, it will post and boot all the way to windows, but will lock less than a minute later. If I reset it will post and lock before or during the windows splash screen. If I reset it a second time, I may or may not get any beeps. If I do, it locks after only one or two (I think there are three) beeps. If I reset yet again, it will not beep at all. Almost as if it only works when cool, and works less when hot. During all of this, all the lights, case to keyboard, all the fans (4 case, 1 PSU, 1 processor, 1 mobo, 2 videocard) spin, all the drives spin up and the mouse led lights up. It just doesn't beep or start the bios or anything.

One guy I spoke to suggested it was a processor heat issue, so I dusted everything and put a 10" house fan pointed at the processor, while leaving the heat sink and proc fan in place. No change. The proc fan is spining fine and is working well as far as I can tell. I also took off the heat sink and respread the heat goop.

I figure it acts like a mobo or processor problem, but the fact that I can get it to start windows sometimes confuses me. Other possible causes that have been suggested are power supply and video card. That doesn't leave much else in the computer and I would like to narrow it down before I start replacing parts.

The system:

Athlon 1900
512 MB Ram
Soyo Dragon Plus! Mobo
Nvidia 4200 Video card


Can anyone out there help?

Thanks in advance.

I will admit that it letting you boot sometimes and not others is kind of strange but after what you have describe I would say that it's the hardware. Now I think your Power supple is fine if it were that I would think that you would just lost power not lock up. If you have another computer or a friend/store that would be will to test the parts for you I think that would be the best thing to do. But I would say it's a safe bet that it the hardware that is causing the problem.

__________________
If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization.

I think I have narrowed it down to the mobo or the processor. Short of buying a new one and installing it, how would I test which it is? are there stores that I could take it to that have the ability to test?

Thanks.

That would depend on your area. Here I have two or three stores that do it. You could call and ask a few small computer repair stores that would be a good place to start.

__________________
If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization.

Check to make sure that the motherboard is properly (grounded) screwed in the case.

__________________
Web Hosting Tips | Career Advice

I would've said heating, but you testify all the fans are working. I'd imagine it's a mobo thing, a dodgy processor wouldn't work at all in my opinion. Have you tested all your memory sticks? It's amazing what dodgy RAM can do!

GF

powersupplies are usually inexpensive (relatively) and fail often - particularly if you got a cheap on in the first place.

I would buy a new one, a good one, Antec or Enermax are well regarded. Be sure to get enough power for your system. I just bought a good one for 65 bucks.

If that doesn't solve your problem, you have at least narrowed down your search to probably the motherboard.

Check out this link for a good review of powersupplies. It is a little outdated, but the manufacturers are still around. I would trust those that produced good products as of the date of this article. Also gives good summary of the types of problems you can expect from a failing powersupply.


http://www6.tomshardware.com/howto/20021021/index.html

To everyone who posted, thank you.

I finally figured out what the issue was. I took the Processor and the Motherboard to a local shop and had them test them in their system. Turns out the Motherboard was toast. I have purchased a new board and the problem is gone.

Too bad I didn't get to you first! I could've told you that after the first post :-P

On a more serious note, please monitor the output of your power supply. If it was a power outage that indeed caused the problem, your power supply could be offering unsafe voltage to your computer, which will degrade the parts and render them useless. I know because it happened to me after I went to a LAN that had several power outages.