I think its a bad PSU....but wanted Experts Opinion

My PC was working fine when I came back last night. I turned it off and went to bed. This morning when I tried to turn it on, it would only partly turn on. The LCD Temp gauge in the front shows the temp. Even DVD ROM light goes off, and I can even see the keyboard being detected. However, the CPU heat sink fan doesn't rotate, neither do I hear the scratching sound that I normally hear when HD is detected.

I think its my PSU, but wanted to get opinion from the experts...
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Gary CaseRetiredCommented:
Power supply is certainly a good candidate; although not the only one.

Since you can "see the keyboard being detected" the CPU is functioning and the BIOS POST code is at least starting to execute.   Do you have any video?  

This could be a defective motherboard, but I'd try a new PSU first.

Does the computer actually boot?  My computer's fans only come on when necessary.  How old is the computer?  What temp does the temperature gauge and what kind of processor do you have?  If the power supply or motherboard were defective, it would be more likely to not come on at all.  May just be a bad fan.  Exactly how far does it go in the power-up process?
Depending on how the PSU failure occured the motherboard might be damaged too. So we have a good chance of both being defective.
A visual inspection can tell you a lot also

burst or popped condensators can cause a lot of trouble, by partly working and failing in the beginning.
Though this usually gives a particular odor.

Checking the PSU can easily be done by measuring the voltage and amps-levels.
I think that you can find a schedule on voltages on the wires on google.
f I'm not mistaken you'll get voltages from -5 0,2,5,7 and 12.
do you have a display? if not, it can be a bad video card. Try to reseat it or try another, even a cheap PCI video card will do for testing.
>>    the CPU heat sink fan doesn't rotate   <<  and the other fans? do they rotate? otherwise, you can have a bad cpu fan, locking your PC
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