Help Please - Computer always on, but won't boot up.

[baffleddude]

Recently my computer started to "flicker" turning the case/cpu/ps fans on and off when shut down. If unplugged from the wall, and plugged back in the next morning, it would boot up immediately (without my pushing the power button). I started to leave it on, to avoid this.

Yesterday, I was gaming and it shut off, but all the fans were still going. I haven't been able to get it working again.

Now, when I plug the power supply into the wall, all the fans in the computer start up, but it won't boot up. If i press the power button ("click", or duration press) nothing happens. The hard drive LED on the front of the case stays solidly lit, no signal is sent to the monitor, and I don't think the hard drive starts up. This is all the computer will do.

I checked all connections inside the computer, and trimmed it down to only these parts...

400W PS
ASUS A7N8X Motherboard
160GB Seagate HD
Athlon XP 2600+ CPU with new fan
GeForce FX 5200
2 - Samsung 256mb PC3200 non-ecc ram
(system has Windows XP-Pro with sp2)

I have tested the mobo outside of the case, to ensure no shorts. Same situation. And my recent temperature monitoring, before the computer stopped working, showed everything to be in great shape.

Oh, also, when it's plugged in, the Standby Power LED on the motherboard is lit.

I also tried clearing the CMOS, that did nothing.

I can usually fix my computer when it goes screwy, but after 8 hours of this, I'm gonna try for any and all help out there.

 

[Tedster]

sounds like your automated switch in your power supply unit has gone bad.
Try replacing the PS.

 

[baffleddude]

Weird. This power supply is less than a month old. I did put in my old powersupply to see if there was any difference. With the old power supply, everything is the same, except the fans will only keep going for a few seconds, then they all stop and the comp lights go out...

 

[baffleddude]

I just pulled out another old ps from my boxes, it does the same as my new one. When plugged into the wall, the fans all start up, the hd LED light is on, and the power standby light on the mobo lights up. But it won't boot up.

 

[Tedster]

That may be why you have problems. If your old PS died or was underpowered, you may have overheated and strained your components. The new power supply was powering damaged components. It's possible, but not definate. Another possibility is you have a defective component that is shorting and causing strain to your power supplies.

 

[baffleddude]

Argh, looks like I need to try and salvage what I can from this system, and fill in the rest with new parts. And get a UPS, in case its the electrical in my apartment that's causing problems.

I haven't been keeping up with recent hardware technology...is there a reliable mobo that can use my current ram (listed in original post) and also use a cpu of at least 3ghz speed?

Thanks