Computer not turning off

[SlushPuppyNinja]

Hello, I was wondering if anyone could help. Recently, I have been coming across an issue by which my PC will never properly shut down. I click shut down and the screen goes to black, the lights go off on my keyboard and mouse but the computer remains on. The only way to shut it down is to knock the switch on the PSU. However, when it comes to turning back on, it won't turn back on unless I unplug the PSU from the wall, clear the cmos and drain all power from the board and PSU (note this is extremely sketchy and only works after about 20 minutes of messing about). Obviously this resets my overclocks and is a pain as I have to spend about half an hour getting the computer to turn on. What's the issue here? Is it software or hardware based? I've heard it's the PSU but it was working find just a few days ago. No hardware has been replaced at all and nothing inside the computer cade has changed either.

My PC specs are:
- AMD FX 8320 @ 4.7GHz
- Gigabyte Ga970a-ds3p
- Corsair H110i GTX
- 16gb Kingston HyperX Fury DDR3 @ 1866MHz
- Sapphire Nitro R9 380X
- Western Digital Caviar Blue 1TB
- Transcend 128GB SSD
- SanDisk 250GB SSD
- XFX 550W 80+ Bronze psu (non modular)
- Thermaltake Core V31

P.s. There is more than sufficient cooling in the case with a total of 7 case fans giving a slightly positive pressure case. My GPU never gets hotter than 70 degrees and CPU rarely breaks the 60 mark either.

 

[Midori_Tux]

Off the top of my head, open powershell or CMD and run powercfg -Energy. This command will show you what is happening during shutdown time and any other problems with shutting down components or devices with the machine.