when i power up, FANS turn and LEDs blink for a few seconds, then computer turns off - HELP!More information required.what more can i add?  power supply is OK, reset and on/off switches ok - machine just won't boot up and runHow how has the probleem been caused? Have you tested all the hardware on different machines? Is the machine newly built?I have had the same problem with a few of my older machines.  I have determined the problem to be the power supply.  Basically it turns on and then turns off,  similar to it being shorted out.  

My reasons for assuming it is the PSU is because when i disconnect it from the system and attempt to turn it on the fan in the powersupply "TWITCHES".  The power supply is only active for a few miliseconds and starts to run the fan.

I would like to know if there is a specific cause for a powersupply to act like this.   You have used the same PSU in all the older machines?
No.  All the systems i have recieved with the problem were given to me by friends and family who couldn't fix the problem (their computer wouldn't turn on).  To my knowledge the powersupplys were never used in any system other than the one they were originally distributed in.What brand of PSU are you using? Are the PSU able to provide the systems with enough Wattages?Does the mobo show any sign of .....capasitors leaning over.....any smell of burning.??i would take out the cpu .....scrape the bottom of it.....and apply artic silver paste...and replace the heatsink....and check you have not damage the cpu pins......and use gloves grease kills CPUS.. AND rember esd**** be careful.........unplug it ....and earth your self

you already no this







i did check the insides of the PSU.  Nothing seems damaged.  I originally looked to see if any caps exploded but saw no such thing =D.  Also i looked for any signs of burning and smoke.... even smelled it....      smelled like fish btw until i VACUUMED out the dust.

Anyway FRANK...  try a different PSU in your system.  in one of my afflicted systems this didn't help but another wone worked fine after i replaces the PSU.