Do I have a short circuit? PSU, or?

[Scotty S-15]

3 y.o. ASUS tower, 400w PSU. For the last two days the computer just shuts off. wham, gone. Starts right up and is OK. Twice now, it has actually dropped out my UPS, had to reset the UPS. That's what makes me think it is a short. I unhooked the UPS last week trying to isolate this clicking sound, still clicked, so I hooked it back up.

The clicking sound? I'm sure it is related to the crashes. It started maybe 10 days ago, it is an intermittent click, actually a pair of clicks. A click...1-second-pause...click. And fairly loud, sounds like a relay might sound. Every five minutes, sometimes hours in between. This did not seem to affect the computer operation, but sounded ominous. For the life of me, can't pinpoint where it is coming from. At first I was convinced it was the PSU making the noise, now, sounds more like the MB? I've unplugged the DVD drive to eliminate that, and don't think it is the HDD.

Any thoughts are appreciated.
thanks

U-P-D-A-T-E:
Finally after camping out with my head in tower for hours, finally, had my ear against he HDD, and I'm 99% sure it is the HDD that is clicking. But, is that the cause, or just a symptom?

 

[Karsten75]

Often hard drives make clicking sounds when they are about to die. The rest of the symptoms don't gel with that. Crystal Disk Report is a good reporting tool on harddrives - just don'w install the crappy bundleware or you will have another problem.

If you have a PSU tester you can test voltages (not loads). http://www.newegg.com/Product/Product.aspx?Item=N82E16899705003

Some (most new) motherboards have diagnostic POST LEDs. That may give you a clue.

Removing as many as possible components may help to isolate the cause.

Running Speedfan, Speccy or Open Hardware Monitor may give you an insight into component temperatures and voltages.

 

[Scotty S-15]

Thanks for that Karsten, looks like you were replying just as I was updating my findings. So yes, looks like the HDD.
Hard to believe that it can create enough current draw to shut down my UPS... and still be running? As you said, those symptoms don't gel. Maybe I get a new PSU also just to play it safe
I did order a new HDD 2 days ago, should be here tomorrow. Think I'll try to give the HDD a rest until I can clone the new one.