Constant power cuts

[arsenalbates]

I have a desktop computer that will just cut out at random events (not restart just hard power off) I thought it was ram so I did some ram tests before booting from the hard drive and it did it again (that rules out the hard drive and the software side of things). I then tried the ram test again and it passed twice so I know its not RAM.

Then I thought of overheating CPU so I ran prime 95 and it ran for quarter of hour without cutting out. So that rules overheating out. Also measured the temps and they were high but still the computer didn't cut out.

I then thought PSU, tested it and voltages seem fine and there is more than enough power to power the rig.

The only things that I didn't test was the graphics card and the motherboard, it dont blue screen and restart it just powers off as if it was pulled out from the wall.

Has anyone got a clue on what could be the problem here as I am baffled.

 

[krone6]

Measure the change in voltage on the outlet itself. Could be voltage gets to low or high.

 

[~Darkseeker~]

1. Power unit overheating - This can happen if any of it's fans or vents are obstructed - this is especially relevant if you have a case with a bottom-fixed unit.

2. Faulty power cable/power strip

3. Faulty wall socket, or damaged wall socket.

 

[arsenalbates]

So this sounds like a psu problem new psu should saffice?

 

[cboucher]

Try running the PC from a completely different room on a completely different circuit before replacing any parts. This sounds like a wall voltage issue...

 

[arsenalbates]

Right. I will pass this info on. Thanks for your help.

 

[Indigo]

Aye, if it's not a wall voltage issue, try swapping the PSU out with another one to be sure. You never specified what the power supply is, but if you paid less than $40 for it and it weighs 12oz for 400+ watts, it's probably not a high quality unit.

On the same tangent as the power though, does that circuit share with anything else in the house that might introduce instability such as a motor or compressor? They can be very harsh on electronics components, especially if you're just using a power tap instead of a good surge protector (a power tap is just a strip of outlets, usually has no power light to show that it's on, but they might have a power switch, and on the back it'll just have markings that say "power tap" or "power strip" - if you can't find anything that says xxxx joules, or "surge protection" then it should probably be replaced.)

 

[dude_56013]

Just because you tested the PSU doesn't mean it's not faulty/failing. Many times, the correct voltages will still read out because it's not under load (i.e. nothing connected to it to read the rail voltages/amps).

 

[arsenalbates]

Update : I have been doing a bit of trial and error and notice two of the four ram modules were newer. I took these out leaving the original 2 x 256 modules and the computer has run for about 2 hours without failing. then I returned the new ram and took out the old ram and it started to power off again. unless it was coincidence I think that its the new Ram that is faulty (however it did pass a full memory test). the two matching pairs were at different frequencies, does this make a difference and could this have caused the problem ?

 

[graham7773]

cboucher, I had the exact same problem and after reading your post, jetted my power cord and replaced with another known good one. Problem solved. arsenalbates, I hope your problem is that simple.