computer doesnt boot, just stays there... need help!

Well, i have a problem with my secondary rig, it has been working flawlessly until like 2 weeks ago, since like 5 years ago, its specs are:
pentium 2 based 500mhz celeron
192mb RAM
CD-RW
CD-ROM
6gig HDD
16 mb Rendition verite video card
250W PSU

lately when im to turn it on the pwer LED just lights up and it stays there.... so what i do is unplug the power cable form the PSU, wait around 10 seconds, plug it back and bam! it works, well i did the same thing today and it didnt... i just turn it on and it lights up, the cd rom lights up for about 2 secs and then turns off, and stays liek that....
i tried clearing CMOS already, no result either by jumper or by removing and reinserting the battery...
what could be causing the problem? my first guess would be the PSU... and btw the psu fan isnt working well... i guess its a sleeve bearing and you know what happens to slee bearing when they die... they just stop and theres nothing you can do
any suggestions?
my dad says he will go buy tomorrow whatevers wrong, it just has to stay under 50(since im upgrading my main rig soon, and i think this is going to him, and that one is going umm.. somewhere), so what should i tell him to get?

any help is greatly appreciated,
Kino

I doubt its a PSU problem. Usually, when a PSU goes, it either goes completely, or it causes system instability. Remove all components except for the bare essentials: CPU, RAM, and video card. I doubt that doing this will fix the problem, but its worth a shot anyway. My best guess is that something went wrong with the motherboard, but you should never assume its the motherboard until all other possibilities have been exhausted.

bump

Could you give us an update? Did you try what I suggested?

still the problem
tried to boot up with cpu, ram, mobo, video and HDD... no workie
cpu, ram, mobo, video... no workie
cpu, ram, mobo.... no workie
tried booting with each one of the ram sticks (one at a time) and still no workie?
maybe its the mobo?
i also changed the mobo battery (the clock-looking one), also cleared CMOS, grrrr!
any other suggestions?

It is definitely either the motherboard or processor, though it is really hard to say which one it is. I'm leaning more toward processor since you said that the CDROM light comes on when you push the power button. That suggests that the BIOS is still at least partially functioning.

Unless someone else has some better advice, I would say that your best bet is to either try the processor in a different, compatible computer, or try to swap out that processor for a known-good one. But be careful, if the motherboard is bad, there is a small chance that it will fry whatever processor you plug into it. The processor might also fry whatever motherboard you plug it into if it is bad. The chances of either of these happening is slim, but it is something you should be aware of.

Ok i've had similar problems. When system starts watch the HDD light[ if it works or n0t] and see if it is blinking as normal. if n0t it sh0ws if def n0t your video card. Now i'd try making sure your CPU ahsn't move aronud at all. I had a k6-2 that would turn on, power LED and HDD LED would come on, HDD would blink abnormally and couldnt figure problem. So i took out CPU and placed it back in, and it w0rked....

I hate to tell you that I had nearly the exact same problem recently. After pulling my hair out trying to pinpoint the problem, it turned out to be the mobo. It died a slow death which made it difficult to locate.

well i was replacing my system with a 2500 barton one, and give my current rig to my dad (the one in my sig), since he was using the one that excremented out... but i wanted to leave this one as a folding rig or something