Desktop shuts down after putting cpu

[vickgeo1981]

I have an old pc,and it powered on but nothing was shown on the screen,not even a no signal,so i took everything off,clear the dust,revome the cmos battery and cables,then put them back in again, then applied thermal paste,now when i press the start button,it powers on for 1-2 seconds then shuts down,when i remove the cpu and the cpu fan and start it again,it starts and stays on,when i put the cpu again itonly stays on for 2 seconds and shuts down,any ideas???Thanks

 

[njoy_rush]

Can you try the CPU in another board, or do you have another CPU in hand? Looks like a overheating CPU if system starts and then randomly shuts down like that. Do you hear any beeps coming from the motheboard, if not, is the speaker/pieso plugged in the motherboard?

 

[darren0000]

seriously mate, try a new psu

 

[darren0000]

check the board for any swolling or leaked capacitors, check cpu for any burn marks.