Computer won't power up

[markspeedo]

Hi there:

I have a four year old generic computer with a Pentium 3-866 and a Matsonic motherboard. I have a CDRW, DVD-ROM and a 30G hard drive.

About a month ago, I noticed my computer was off (left on 24/7 most of time, except when traveling). I pushed the start button and it came on for a few seconds, then off again. Then I tried again and it lit up, then immediately the lights went out. My first thought was power supply. Then I read a message thread here and it sort of confirmed that for me, but there were some recommedations about "shorting" and "jumping" and I thought I should ask some more questions.

Anyway, I bought a new power supply, but the new amps are not identical to the old power supply (does that matter??). I installed it and the motherboard lights up inside (a red light) when the i/o switch is switched on. Then, when I hit the "ON" button, the lights on the front of the case lit up for about a second, but went right back out (and wouldn't come back on upon subsequent pushes of the button). The red light stayed on (inside the case) on the motherboard (I haven't seen a "green light" on the motherboard). Also, I didn't hear the hard drive or any of the fans start up when I pushed the start button. Further, the only items I hooked the power supply up to were the motherboard, the hard drive and the floppy drive (the cpu fan plugs into the motherboard - is that always the case??).

Anyway, I'm not a tech expert, but I do change/ad RAM or a network card occasionally, so I'm maybe a step or two above total novice. Any thought or ideas would be very MUCH APPRECIATED!!.. Thanks, Mark

PS When I hooked the original power supply back up, the motherboard did not light up at all, so the original power supply is, in fact, bad (even if there are still other issues). Thx.

[PCTOGO1]

Hey,

If you know someone that has an ATX power supply tester, use that to test you old power supply. Or just use a multimeter to check your voltages on the old power supply to see if they are excessive.

Check your cpu, sounds like your processor may be bad. If you have any questions feel free to ask.

[kipwinter]

It does sound like the cpu is shot. At first glance... Did the sys. post at all when it powered up? (memory count up "hit delete to enter setup ect)? Clear ya cmos and keep ya fingers crossed ;-)
Let us know and good luck !!

[sevenal]

any beep codes at all?

[INTEGRALE69]

This also sounds like a short somewhere in the computer the old psu is detecting it straight away and shutting down to protect itself the new psu may not detect it as fast or it might be down to the different ratings on the psu, typical places for shorts are usb ports but I'd check every possible connection on the computer for damage, also have you disconnected all your peripherals I'd even disconnect everything but the mains just to see if the problem happens with the base unit stand alone.