Desktop power-up issues

[s3rius]

Hi guys,

For some time now I have issues with starting my desktop pc. Sometimes nothing will happen when I press the Power button, sometimes it'll start just fine. If it's one of the days where nothing happens, I can only help it by completely removing the desktop from the power net (e.g. pull the plug) and re-plug it again. Immediately upon re-plugging it it'll start as if I've pressed the Power button.

The problem appears very irregulary, it started happening about once a week, a few months ago. It gradually became more frequent, sometimes completely disppeared for a week or so, then re-emerged.
At first the unplug-replug method worked, now I usually have to do it several times until I get my pile of circuits started.

However, once the pc is running, it'll run dependably without randomly shutting down, even at high power draw. The pc also doesn't completely lose power when the problem occures (mainboard LED's, etc are still lit up)

I guess it's the power supply unit (A Super-Flower Aurora 700W) but due to the weirdness of the problem I'm not all too sure.

Anyone expperienced similar problems or knows a way to figure out if it's the PSU crapping out?

Before I buy a new PSU for 100€ I would like to make sure I'm actually replacing the faulty part.

 

[Accname]

This is just a guess but did you try to look at the cables between your power buton and the mainboard? Maybe somethings loose?

 

[s3rius]

I forgot to mention - same thing happens when I use the power-up button directly attached to the mainboard.

 

[Slapshot136]

hard to tell, you might want to grab a multi-meter and measure the voltage during start-up (make sure the 3.3, 5v, and 12v are all within spec), but as far as measuring the harmonics, unless you have an oscilloscope, that would be hard to detect

 

[s3rius]

Aight I'll see if I can get my hands on a multi-meter.

 

[rover2341]

I have a simmlar problem on my computer. I thought it was my motherboard, but i replaced nearly everything. Expect power supply and graphics card. So my guess is in my case its the power supply or graphics card going crazy.

The fact it sounds so close to the same thing, and your claiming no real draw from other things (aka Mega huge video card) then...my guess from my experience is likely the power supply.

 

[Slapshot136]

Iand your claiming no real draw from other things (aka Mega huge video card)

somehow I think s3rius is likely to have a "Mega huge video card".. since otherwise he wouldn't need a 700W PSU

 

[Monovertex]

s3rius, if you do have a large graphics card and integrated graphics alongside that, care to try with the graphics card removed if your desktop works? Actually, you would see if your computer power ups at all, so I think you can remove the card even without integrated graphics.

Same goes for any HDDs, you can remove those and just start the computer like that, see if it powers up.

Note: when removing components, they will draw less power, so it's possible that a lighter load on the PSU got it powered, not necessarily that the component is damaged. So you should test multiple times and try to determine which situation is real. Best way to do this would be to test with other components, which you are sure they work and they also have close power requirements.

Of course, simplest way to go, when suspecting it's the PSU, is to just try a working PSU from a friend or something and see if it happens again .