Desktop power supply defect?

[27POP27]

About a week ago my desktop didn't want to start after I turned the electricity on (no lights, nothing), then I waited for 10min (with the electricity on) and THEN the PC wanted to start. This has been going on now with varying "charge" times from instantly to 10 minutes for a week. When it starts the PC works fine, but today it didn't ever start :<
Is it the power supply (Corsair AX850)? I'm really suspecting it, but the case here is kind of special.

I have checked the cables and cable-houses and they are fine.

 

[dextermat]

Could also be the power button, does it feel loose.

Also could be mobo dyeing.

 

[juanrdp]

You could make a couples of test:

For the PSU dyeing, short circuit two of the pins of the board connector from the PSU (http://www.instructables.com/id/How-to-power-up-an-ATX-Power-Supply-without-a-PC/?lang=es) if it works, probably would be the Mb or the power button.

If that works, short circuit the power pins of the mb with a cable, if it allways start it would be the button.

Hope it helps.

 

[27POP27]

Could also be the power button, does it feel loose.

Also could be mobo dyeing.

The power button is firm, and so is the restart button, which should also start the PC. The thing here is that the PC starts just fine when I see the lights on the GPU turn on inside the PC (after varying times). It's like the PC is "charging" up, where it's "Go!" when the lights turn on.
I've also considered the MOBO being the problem, but I'd find that weird since the PC NEVER have had any unexpected bluescreens or errors for 4 years, including recently when it actually starts.

 

[Rookie_MIB]

It could be a few things.

1) Switch. Believe it or not, I've had a switch go bad (wire coming out of the switch frayed/broke). If you have a separate reset switch and power switch, you can swap the wires at the mobo and test it that way. If you don't, just try shorting the two pins and the computer should turn on. If it doesn't, it's not the switch.

2) Mobo. If it's an older motherboard, your capacitors could be going bad (they have a finite lifespan) which could cause issues turning on. Since the turning on of the power supply in the ATX spec is routed through the motherboard, there are potential areas for issues to arise.

3) PSU. If you have a newer Mobo, it -most likely- is the PSU. Much like the motherboard, they have capacitors and such which degrade with time and if it's an OEM type supply or a rebranded type it could be a little on the iffy side with regards to quality. The AX-850 though is a pretty decent unit, as it's built by Seasonic who makes some of the best.

How old is the mobo? (and who made it). Also, how long ago did you buy the PSU - they were released in late 2010 if I'm not mistaken.

If you have a spare PSU, try swapping that (after removing any GPUs - no point in overloading things - we want to narrow down issues...)

 

[27POP27]

It could be a few things.

1) Switch. Believe it or not, I've had a switch go bad (wire coming out of the switch frayed/broke). If you have a separate reset switch and power switch, you can swap the wires at the mobo and test it that way. If you don't, just try shorting the two pins and the computer should turn on. If it doesn't, it's not the switch.

2) Mobo. If it's an older motherboard, your capacitors could be going bad (they have a finite lifespan) which could cause issues turning on. Since the turning on of the power supply in the ATX spec is routed through the motherboard, there are potential areas for issues to arise.

3) PSU. If you have a newer Mobo, it -most likely- is the PSU. Much like the motherboard, they have capacitors and such which degrade with time and if it's an OEM type supply or a rebranded type it could be a little on the iffy side with regards to quality. The AX-850 though is a pretty decent unit, as it's built by Seasonic who makes some of the best.

How old is the mobo? (and who made it). Also, how long ago did you buy the PSU - they were released in late 2010 if I'm not mistaken.

If you have a spare PSU, try swapping that (after removing any GPUs - no point in overloading things - we want to narrow down issues...)

1. Hah ok the GPU light actually JUST lit up (after 50 min!) and the PC instantly turned on when I pressed the button, AKA its not the button.
2. The PC just started and works perfectly fine atm, would that exclude the MOBO? It's a ASUS P8Z68-V PRO Z68 S-1155 ATX btw.
3. PSU bought in 2011.

 

[Rookie_MIB]

Given a choice between the Mobo being bad, and the PSU being on the way out, I would tend to believe it's the PSU. The mobo is a solid cap design which tends to be a bit more reliable (older electrolytic caps had a tendency to be a bit flaky) and ASUS makes a pretty solid board.

So, I'm guessing a new PSU might be in order, and of course, a PSU is a cheaper and easier thing to test than tearing apart the entire computer.