Computer turns on for a split second then shuts off

[ericmartineau1978]

Hey guys,
I got the same problem today. My computer working for about 6 month whit no problem. But tonight i came back from work and i found my Pc shutdown. Wird cause he always up and running. Anyway, try to start him up, working for like 2 sec. Hum no bip, no time to overheat. Well turn the power-supply off whit the switch behind it. After maybe 4-5 try the pc start up. Everything now work fine but i am almost certain it the power-supply. Cause this power-supply is 8 year old and the component of the computer asking him all the juice he got. So tomorrow i will get a new one. In my case like i said this computer is working for a long time ago so there is no way it was the video card, memory, cpu, name it!. Trust me. Its a deductive way to work.
Good luck

 

[deg1223]

if anyone comes across this post and none of the above solutions work, you could also try clearing the motherboard CMOS and even try replacing the CMOS battery. that seemed to clear up the problem for me.

 

[turbotown]

I read a few answers for your problem but never saw any mention of the power supply other than "it's fine'.
You have to do a check of the psu by installing a known good psu or a new psu that you are confident works.