Computer wont start with cpu in

[tropmex]

Hello,
My computer wont start.
Hit the on button and the light on and cpu fan on for several seconds and stops. I have tested the power supply unit it works fine. I found the CPU fan was really dirty and almost blocked by dust. I cleaned it and put the heat sink + fan back without thermal compound for temperary test. Same problemm. I pull out the CPU and start the computer and all the fans work just fine. My question is, does it mean for sure the CPU is bad. Will that make a difference if I reapply the thermal compound?
Your help will be greatly appreciated.

 

[kinth]

doesn't sound like overheating as that usually atleast gets to POST then crashes.
have you checked to see if the cpu you have is compatible the mobo ?
is your psu enough to power it?.
can you give us some specs.

 

[o1die]

Please list your complete system specs. Is this a new build?

 

[tropmex]

doesn't sound like overheating as that usually atleast gets to POST then crashes.
have you checked to see if the cpu you have is compatible the mobo ?
is your psu enough to power it?.
can you give us some specs.

Thank you Kinth for your quick response.

It is a 4 years old computer and it had been running just fine. So I assume that there is no compatibility issue. I was try to find out the problem by ruling out posibilities one by one.

I shorted the green and black in the 20 pin plug and the power supply unit fan was running continously.
Is that enough to rule out the power supply unit problem?

Also, does it mean anything if all the fans can run continuously with the CPU out?

Thanks again.

 

[kinth]

well im no expert on electrics and wiring but isn't green usually a earthing/grounding wire?
if youve shorted any wires youshoulden't be trying to run anything with it, a shorted wire could fry your entire system and in an extreme case could fry you.

how long have the wires been shorted have you only just shorted them or have they been out for ages?

if there are shorted wires in the 20pin plug then theres most likely not enough power coming from your psu. it's a 20 pin plug for a reason if it was meant to run on 18 they would of made it 18

even if you have managed to run it with shorted wires for a while i would never recommend doing it. it would only be a matter of time till something wen't wrong.

 

[1965ohio]

I think he just shorted the wires for a test. But just because the fans spin up does not rule out the power supply. It can still eek enough juice to spin up the fans.

Other that just dead, when you hit the power button, does anything happen? Do that fans spin up for more than a 60 seconds? Do you hear any beeping sounds? Anything at all?

 

[beanoslim]

Unplug everything, press power button a few times.

Reset bios including removing battery for 15 mins.

Plug back in and try, solves a lot of issues.