FIXED: Computer won't POST, and I'm outta ideas...

[wakka15]

EDIT: Thanks to mechBgon... it turns out it was the power supply after all. After listening to it a little more closely, I heard an odd hum emanating from the old psu (I'm assuming it was not good). Luckily I had a backup PSU (another antec), so I think I'll be all right for a while ::knocks on wood:: Thanks again, guys, for the help.



Processor: Athlon XP 1600+
Mobo: Shuttle AK39N
Memory: 512 mb PC333 DDR RAM (samsung)
Vid Card: NVIDIA geforce4 ti4200 128 mb

Problem: Came home from work one day to find the monitor blank, and after mashing the keyboard like an enraged chimp, nothing brought the monitor to life. I assumed the computer simply froze. Rebooted and the computer worked fine for about 10 minutes before freezing up again (monitor went blank again). Went to reboot this time and the computer powered up, but would not post. The fans for the power supply, heatsink, and videocard all power up and start spinning just fine, but I get no video (no post), no beep, and hear no hard drive activity (so no boot).

Disconnected all components but the bare essentials, and tried again. Same result - power but no video (no beep-code, no post). Tried resetting the CMOS jumper - nothing. Tried taking motherboard out of case to see if it was a short, still nothing. After messing with it for about an hour, I DID manage to get a beep-code - I had the vid card and processor/heatsink in, no memory, and got some long beeps (related to RAM, but I can't recall exactly what they signified, bad RAM, perhaps?), but unfortunately wasn't able to consistently replicate this.

At this point, I'm thinking that either the motherboard, processor, or memory has gone bad, and I'm leaning towards the RAM, after hearing the processor beep just that once... I DID overclock the processor several months ago, but changed the multiplier back to normal two months ago after the system started freezing, so it's possible the processor just up and died, I'm not too sure.

At this point, it's looking like I definitely fried something, but I need a little help to figure out exactly what. Any Ideas?
was

 

[mechBgon]

Do you have any other computers that you can use for testing purposes? The power supply might've failed too, and trying a known-working PSU (preferably good quality and at least 300W) would help establish whether the PSU has failed.

 

[redbeard1]

Any puffed up or leaking capacitors on the motherboard?

 

[wakka15]

Thanks for the suggestions.

As far as capacitors go, I'm at a bit of a loss as to exactly what they look like (I'm assuming they're the cylindrical battery-looking things scattered about the mobo, in which case, they look ok to me). As far as I can tell, the motherboard looks ok.

Luckily, I have a gutted backup machine with a working power-supply (Antec 400W, I believe) that I can test, so I'll get back to you after work today...

 

[snidy1]

Did you try resetting the bios?

 

[Zepper]

Boilerplate-01:
. Common causes of failure to boot (no video, no beeps):
1- RAM, CPU and/or AGP video card not seated properly, or a bent pin.
2- Drive data cable on upside down or only on half the pins or shifted . a pin or two (usually Floppy or Zip drives).
3- CMOS needs to be cleared (AC power must usually be disconnected or . attempt to clear CMOS may fail) Unless your mobo does not use a power-off CMOS clear - check your mobo manual for specific info.
4- On some new mobos there is a CPU protection feature (esp. on Asus/Asrock Athlon/Socket A mobos) that will not allow the system to start if there is no fan (or a fan without a working speed sensor wire) connected to the fan power connector on the mobo (specifically marked "CPU Fan"). If you tried to start your machine without a fan properly connected, you have to attach a proper and working fan and clear the CMOS before it will boot.
.bh.