Motherboard - Electronic Behaviour

[gabrimor]

Hi!

I Bought a dead motherboard, months ago. It was an Asrock Z77 Extreme 4, which is a high end motherboard.

I knew it was defective.

Tried to start the motherboard with the motherboard bower button. Nothing happened.

Jumped the PSU and the motherboard started.

Since this event, the PC works normally.

And no, I don't have to jump the psu anymore. Now power button works.

An Asrock Z77 Pro 4 from a friend showed the same problem.

I tried the same solution.

Dice. The motherboard are working again, and he doesn't need to short the psu anymore. It was just one time.

What you think about it?

For me, it's not something related with chips. Looks like an electronic problem, from a mosfet, a cap...

Thank you!

[retiredfeline]

What you think about it?

You lucky devils. :+

[Rasz]

probably first steps of https://www.eevblog.com/forum/repair/mainboard-suicide-after-sleep/ as described by me in https://www.eevblog.com/forum/repair/mainboard-suicide-after-sleep/msg2983902/#msg2983902

problems start off with mild symptoms of not wanting to power up, but later turn to power supply starts but nothing happens. Asrock used to RMA those boards without question suggesting they knew exactly where they screwed up.

[gabrimor]

Thank you Rasz!

I gave a read in your links, ans I think my problem is similar, but maybe, a little different.

My friends Z77 Pro 4 is turned on and off many times a day, and, last night, the psu was off the wall.

It was off the wall for around 18 hours, and today, turned on normally.

Hard to explain, don't you think?

Thank you for the support!