Computer not working right

My computer has been locking up randomly on and off for months now and I don't know what was up with it. It hasn't locked up for a while now and last night it just randomly turned off. No windows error, no power problem, just turned off.
I tryed to turn it back on by pressing the power button but I get nothing. The light on my mobo is still on though. I unplug the power cord and plug it back in and hit the power button again and it turns on. I get to the desktop....open firefox.....navigate to ozzu.....and it happens again. I do the same thing (unplug replug....) and it doesn't make it to the desktop before shutting down. Sounds like a heating problem right?
Well, I go into my BIOS on the next boot and check my temps. My CPU is running at 49C with system zones 1 & 2 at 36C. That is a hot proccessor! I grabbed a little 12" fan I had sitting around and let it blow into the case I has now opened. Slowly the tempurature of the CPU went UP! It went to 52C and I couldn't take it anymore. At this point I was fanning air in from an open window too and it wasn't helping. I unpluged the computer and let it cool overnight.
I woke up this morning with a feeling that it would work. But I hit power, get lights turning on and fans spinning......1 one-thousand.....2 one thousand.....3 one thousand.......dead. Try again.....same thing. Unplug my graphics card and PCI cards and try again.....ditto. Pull the mobo out of the case and try yet another time......ditto.
WHAT IS UP!??!?!?!?

If it might help, I am running the following:
P4 @ 3.06 GHz
Intel D875PBZ Desktop Board
Windows XP Home SP1


ANY HELP IS G R E A T L Y APPRECIATED!

Sounds to me like your power supply might be ready to die on you. The excess heat might be from unstable power levels. Since you have all the tempature sensors, go in your BIOS setup and look at your voltage readings. My guess is that they are higher than they should be. Getting a new power supply will probably fix this problem.

bingo! I tryed with an older 350W PSU and it starts up and stays on past 3 seconds. I didn't hook up all my stuff cause I am lazy and 350W isn't enough for my computer......especially not after the upgrades I am about to make.

This power supply is only a month old though! What is up with my PSU's always dying on me? It was only $15 but still!

I am going to go get some new components (new mobo, PSU, and cooling system [overclocking]) and I will let you guys know if it quits for good.

Well it died after a month because.... it was only $15.

Power supplys are complex little gizmos, and you pretty much get what you pay for.

http://static.tigerdirect.com/html/powe ... guide.html

49c isnt hot for a Pentium 4, thats about normal shouldnt be anything to worry about.

mine runs at 35 and once in a blue moon hits 40 under load. My power supply was $150 and still, from time to time, the power seems to get unstable and at that point, I turn the computer off or put it into standby for a while and both seem to help.

Well, the P4 I have is supposed to be the coolest running P4 that is over 2.5 GHz. It says in the documentation that 48C is the high point for it. I usually see it at temps between 36C and 42C....not to mention that it was idle.

Ever opened up a PSU lucassix? They look just as complex as any hello world program. Maybe cheap ones just have *plum* materials?? Well I will buy a new one soon. For now I'll just run my 350 Watt.

Yes. Just another bullet on my list of things that have shocked the hell out of me. Just a tip. When you go to discharge those big capacitors, make sure the other end of your ground wire is actually grounded...

muahhahahaha, I did the same thing.

Well, I am running off of an old 350-Watt PSU with no problems thus far (just over 48-hours) so I guess we got it! Thanks!