Do you have an LED on the MB that stays lit when the PC is powered down? These usually indicate the presence of the 5v needed to start the computer. If no LED, the 5v isn't there or is too low. A DVM would help. If you know the 5v is present, you can try to force the PS to latch by shorting the green wire on the MB plug to ground. This should immediately bring up the PS and you'd disconnect the ground when this happens. If this does not start the PC, another voltage may be the issue. Your symptoms sound like classic bad caps but your rig seems too new to think that right away. Now, if pressing the start switch causes the fans to twitch but stop almost immediately, the PS has tried to start but detected a load problem. In these cases, my experience has usually been that the PS was inadequate for the job. You could try disconnecting unnecessary hardware to see if the PC starts and, if it does, the PS is too weak to handle the load. Good luck.
Hi,
I have build a PC about 3 years ago. I had no problems like ever. PC sleep and other things.
Recently, whenever PC goes to sleep and if I press power button it would do nothing and just switch off. Whenever it happens I can't even start computer for hours. Usually, after 12 hours it works like a it never happened.
Same happens on Windows 10 and Ubuntu 16.04.
PC speed is fine, no other random outages, I have even checked manually with multi-meter power supply leads and it seem to have a normal power output.
What is weird why the PC won't start for hours and when I say it won't start then even power light or fans won't come up, power supply is not active.
I have even disconnected from mains and pushed power button to o a complete power reset, changed power lead etc. it's all the same?!
Anyone has any ideas?
PS SPEC:
Motheboard: ASRock Z97E-ITX/AC
CPU: Intel I5 4690K
RAM: 16GB
PSU: Seasonic G550 550W 80+ Gold Certified PSU Semi Modular *** Caps
OS: WINDOWS 10 and UBUNTU 16.04 on separate physical drives

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic