Sometimes Not Booting

[Eupolemos]

First, apologies for not posting full specs as recommended, but I'm guessing it isn't relevant. Also, I'm not entirely comfortable rebooting the comp.

 

I'm here to hear if my assumption of imminent PSU failure is a likely mistake.

 

My 5 year old desktop sometimes doesn't boot. It displays the "commercial" for my motherboard and just ends there. No beep, just full stop.

 

If I reboot, it always works fine first time.

 

Yesterday, activating the computer from sleep-mode, weird stuff happened. It made a few angry windows-sounds and my mouse and keyboard didn't work or have power (both USB connected).

 

Rebooting, the mouse still didn't work. I had to unplug it and replug it, but then it worked fine.

 

Does this sound like a PSU issue to everyone else, or is there a good chance I am mistaken.

 

Some of the specs for good measure: Win10 64-bit, NVIDIA 770 GPU, 16 gigs of ram, z77x-d3h motherboard, i5-3570K @3.40 GHz 3.80 GHz cpu, 850watt RX-850AE PSU

 

Cheers and thank you for any helping thoughts - just as much if it's just an affirmative nod.

[IntMD]

PSU or motherboard are my best guesses as to the problem.

[vaiwalker]

sounds like a motherboard problem. i've had something similar happen to me. programs just wouldn't load properly in desktop after booting. programs stopped loading. random hangs and crashes. eventually over a week, it got worse.and finally the mobo died.