Desktop will not power on (but psu green light is on) nor bootup

[mpdeangelo]

Compaq Presario CQ5320F Desktop PC  Windows 7  

product number   AY030AA  (-ABA)

motherboard: M2N68-LA (Narra6)

3GB DDR3   AMD Athlon II  X2 240 Dual Core   64 bit

Desktop will not power on (but psu green light is on) nor bootup

Computer used to shut off intermittently

After pressing the power switch a few times or holding it for a bout 5 seconds

it would come back once is while (very few times).

Then if we let sit over night sometimes it would work in the morning.

Since then I have (I am a little savy with PCs) opened up the chassie.

I have removed all connections except the 20pin and 4pin psu connections.

Tried to start again and no bootup.

I bought a new psu (not an HP one but it is still a compatible 250W).

Still no power up.

I had a 480W psu and tried that still no power up.

They all show a green light on the outside when plugged in,   Even took out some RAM.

Even moved the cmos pins back and forth.  Change voltage switch back and forth in the back of the psu (it is set to 115V).

NOTE: For all three psu’s I was able to jump start them with a power clip and then the fans started to work but still no bootup.  But by using the paper clip was the only times the fan would work.

The only thing I did notice was when the attempt to bootup with the original psu and a vga monitor plugged in, the monitor said “enter power-save mode” and then shut off.

My last resort would be to get a new power switch.  That is the only thing I can think off and of course the last thing would be that my mother board is dead.

(is there a way to check your motherboard with a voltmeter, I doubt it).

Have removed a printer driver and then reinstalled it.  Have hp and windows updates running.  Have Norton 360 and itunes running.  Son has played games on it.  Use yahoo and gmail.

[c0rnel]

Definity something with the motheboard I would say. If the power supplies give out power and using the paper clip trick they power on I would check the motherboard again.

When you take all the ram sticks out and try starting it does the motherboard beep at all?

Have you tried clearing the CMOS using the 2pin jumper or taking out the battery for 1min?

Also try seating the 4pin or 8pin cpu power cable that goes to the motherboard (near the cpu area).

I've also had my motherboard die on me recently (not hp brand).