Front PC button does not turn on, only when I pull mains cable in and out

[domnerus]

Front PC button does not turn on my PC, only when I pull mains cable in and out.

Even when I do pull cable out/in it doesn't always work. Sometimes I have to do it 10 or more times. Than PC comes on, without the need to press front on/off button. Button works when I turn off the pc.

Any ideas?
Thanks

 

[Tmagic650]

The power supply may have become faulty...

 

[domnerus]

Or mobo.... But how to fix it?

 

[Tmagic650]

Take it to a computer repair shop where they can substitute parts to find the bad one

 

[bazz2004]

It's working out what's wrong that's always the difficulty. I'd say that it's more likely to be the PSU or on/off button than the motherboard. If you have had the desktop a long time and the PSU is of low wattage there's a good chance it's that. I've only had a PSU fail once and that was this week. It was over six years old, 250W and when I removed it was a very lightweight model without even a power switch. I just took the chance that this was the faulty component, bought a quality replacement and hoped for the best. I guessed right. You are not supposed to tinker with a PSU because it can retain lethal voltages but a couple of days later I took off the "lid" and visually inspected the components. Capacitors, which are those cylindrical components, often fail so I looked these over. With the PSU there was no clear sign of anything wrong but it looked as if two capacitors were very slightly raised on the top. I'd guess that even the tiniest issue would cause a PSU to be ineffective.