Is my Motherboard going bad?

[Player Hunter]

So I've been experiencing some problems lately with my rig.

After turning off my pc, when I press the power button, nothing happens. There is power to the motherboard, the green light is on, but nothing happens.

I've done a bunch of troubleshooting. I've tested each stick of RAM with Memtest86, both passed with flying colors. I've done the PSU test where you hotwire it to switch on without the use of the motherboard. When I switched it on, the fan started spinning, so there doesn't appear to be an issue with the power supply.

I've run CPU stresstests, no problems.

Does this then definitely mean that the fault lies with the motherboard? From time to time while doing random stuff on the computer, the computer will freeze, the last sound played skipping, and the power button won't shut off the computer. I have to switch off the power directly on the PSU. I've also noticed the clock will have stopped when I last switched off the computer so I have to change the time and date settings to the current time and date. Yes, I've switched the battery, now on my third one.

In order to start the computer, I usually have to unplug the 24-pin motherboard power supply, then plug it back in, then the computer will start again, and run fine, for an indefinite amount of time.

So, will I have to put a new motherboard on my to buy list? Looking to buy the Asus Sabertooth Z97 Mark 1 as a replacement for my current Asus Sabertooth Z87.

Thanks for any help and advice you can offer.

Specs:
Corsair 850W HX PSU
Asus Sabertooth Z87
Intel i5-4670K 3.4GHz
Gigabyte Geforce 760, 2GB VRAM
2 x 4GB stick of Corsair Vengeance 1600 MHz RAM.
Asus Xonar DX Audio Card
Corsair H80i Liquid Cooling
Corsair Obsidian 550D Cabinet

 

[DeViL5o5]

what PSU do you have? sounds like that could be the one causing your issue.

 

[Player Hunter]

what PSU do you have? sounds like that could be the one causing your issue.

Not according to the troubleshooting I performed. It's a Corsair 850W supply, don't remember exactly which of the series, but it was the performance line, the one that says it uses at least 80% of the power effectively. So it's a solid quality power supply.

Edit: It's the 850W HX series PSU. Also, I did the hotwire test as previously mentioned, where the fan turns own as soon as you hit the power switch on the PSU. It turned on and ran fine without complaint, so it seems like the power supply is fine.

 

[DeViL5o5]

yep, that's a good, solid PSU. have you tried updating the BIOS to a newer version?

 

[Player Hunter]

yep, that's a good, solid PSU. have you tried updating the BIOS to a newer version?

Running the latest version (1707).