Asus P7P55D CPU led problem

[KilleX]

I have Asus P7P55D motherboard for one year now. It was working without problem until now. Sometimes when I start-up computer fans go to 100% speed and CPU led is ON all time. On screen there is nothing(monitor is not detecting GPU). This doesn't happen every time. But when it does I must turn off power switch and then turn on computer back again. What should I do? I tested RAM so it isn't problem there.

 

[jaquith]

Welcome to Tom's Forum!

This 'could be' a failing PSU, do you have another that you can borrow from another PC?

First, disconnect ALL non-required USB connections, and if possible use a PS/2 keyboard + mouse. Next, run MSCONFIG and select Diagnostic and restart - does problem go away?

Next, in the Device Manager are there any {?} or {!} devices listed? If so then right-click and delete followed by a restart.

Afterwards, assuming Windows 7, open the Event Viewer and post here any Critical Errors. This will all be a good starting point.

 

[jsc]

Your symptoms also describe a flaky power supply.

 

[KilleX]

I did run system in Diagnostic Startup. Same problem. No critical errors. PC is working well when I start it. It has problems only for turning on. I will now test voltages on PSU.

 

[jaquith]

Then 1. Bad 'electrical short' in Power Switch, 2. Bad PSU; the initial surge in power would again indicate a bad PSU.

edit: to rule-out the power switch, remove the (2) leads on the MOBO and 'short' the PW+/PW- {or as identified per MOBO} with wire or paper clip.

 

[KilleX]

Ok I did following:
Tested PSU voltage and it's good.
Started computer with a screwdriver and problem still occurs.

I think its CPU or MB. If you have any other sugestion please say it. If nothing of these works I am sending mobo and cpu to service(still have warrnity). Should I send PSU too or not ?

 

[jaquith]

{screwdriver too - I didn't lookup you header arrangement}

Certainly it 'could' be the CPU/MOBO, but IF this is a startup occurring ONLY problem then it screams the PSU. If you have an extension cord try a completely different outlet to rule-out 'misc' power outlet issues. Having 'power' vs having Clean & Stable power is another thing...

PSU's are a source of all sorts of oddball incidents; dirty power effects and/or can damage all sorts of things incl {MOBO, GPU or anything it's attached to}. Most PSU's do not have under/over or fault protection. If it were 'me' I would, as I said, borrow a PSU or buy one with a good return policy i.e. Best Buy or similar local electronics supply store.

Clearly, if it is under warranty so is the PSU I would assume.

 

[KilleX]

Ok thanks for answers for now. I am going to borrow PSU from a friend and test it. That should tell me what is the problem. I will post here what I done

 

[jaquith]

Okay - I hope it corrects the problem!

 

[rest]

is there any update ?

 

[KilleX]

Sorry forgot to update topic. Tested with another PSU, problem wasn't solved. I have now sent MB, CPU and PSU to service. When they check what it is I will post here .

 

[KilleX]

So I got back my components and problem was in motherboard. Thank you again for your help