What are the symptoms of a dying PSU?

[Dr.Demento]

I've never really had to replace my PSU since I built my PC back in 06' and my knowledge on PC tech has gotten a little rusty. Can someone refresh my memory? All I know is that my PC keeps shutting off at random moments so I don't believe it's my UPS anymore since I bought a surge protector in an attempt to narrow things down. The inside of my case is pretty clean and nothing appears to need re-seating. What now?

EDIT> I also noticed that the power cable seems to be having trouble staying completely plugged in. Maybe because of this it's shorting out the PSU?

 

[giant384]

1. Overheating
2. faulty psu
3. a loose plug wouldn't short it out but it would shut it off if it loses that connection.
4. Its possible that one of your components are shutting it off.
5. Virus?
6. System file corruption.

 

[Dr.Demento]

1. Overheating

Maybe. I need to check the temperatures somehow, but all my fans are working except 1 outer 80mm case fan and it's not very dusty.

2. faulty psu

Highly possible

3. a loose plug wouldn't short it out but it would shut it off if it loses that connection.

Also highly possible. After all these years, the way the cord sags could be wearing out the connection, thus making it loss power unless I keep re-fitting it.

4. Its possible that one of your components are shutting it off.

What do you mean? Possibly a different component going out?

5. Virus?

Unlikely, but still possible. I don't have broadband, so I don't do much browsing on this PC. Already checked with a few virus scanners with updated definitions, and results turned up negative. Maybe the virus scanners I'm using just suck?

6. System file corruption.

I ran CHKDSK multiple times, and it didn't resolve the problem, but I think that's just for repairing bad sectors. How do I check for system file corruption? (Windows XP Home)

 

[No Limit]

EDIT> I also noticed that the power cable seems to be having trouble staying completely plugged in. Maybe because of this it's shorting out the PSU?

How often does the shut down happen? Not having the power cord seated all the way wouldn't short out your PSU (if your cpu shorted out there would be serious damage), but it can certainly disconnect the power which will shut down the PC. Do you have another cord you can try? How loose is it?

 

[Dr.Demento]

How do you check for system file corruption in XP Home? Do you have to have the OS disc to repair the file?

@ NoLimit:I don't have a spare cord. I'll probably just get a new cord and PSU soon, so I'll just have to wait and see if that's the problem.

 

[No Limit]

For file system corruption it depends on the corruption.

To check the disk for bad sectors run chkdsk /f /r from the command prompt.

To check for corrputed OS files run SFC /scannow from the command prompt (I believe you will need the windows CD for this, can't recall of the top off my head).