This could be an overheating situation. If you are OK with going inside 
the case, you can check for any accumulated dust particularly on fans 
and heatsinks. Be careful of electrical differentials by unplugging the 
computer and touching the case. If you are not comfortable with opening 
the case, you can clean the exterior fans and the case filter, if any, 
and that may be enough for now.

Tom

Sybilgal wrote:
> Hello all, 
>
> My computer recently started shutting down on its own.  Nothing else has
> changed, nothing else going on.   The first time it happened, I assumed I
> did something with the keyboard causing this to happen, but that wasn't it.
> Now, though it will begin to start up, it turns itself off again, even
> sooner.  
>
>
> Can anyone advise me as to a method to diagnose this problem?  I assumed it
> was the power supply, but others have told me that were that the case it
> would not start at all.  
>
> I really don't want to fork out $200.00 to diagnose and then after that, end
> up by buying a new MB, power supply and memory...UNLESS of course, I have
> too!
>
> Any suggestions to assist in this discovery would be highly appreciated!
>
> Thank you all, in advance...
>
> Kathleen LaValley
>
>              
>
>
>   

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