Asus F2A85-V Pro making computer turn on instantly when power supply is switched on the auto turns off.

[scollbusiness01]

Story: The story goes like this... my computer stopped working properly so I took it to my school lab to figure out what's wrong with it. After testing all the parts by putting them in a working computer one by one I found out it was the motherboard that isn't working. So instead of figuring out what is wrong with it, I decided to just replace it with an upgraded version we had in the lab but that one didn't work properly either. The motherboard is reasonably "new" as it hasn't been in any computers that I know of but there are other people that work in the lab and may have done something with it. Anyhow, I just want to know what is wrong with it and how can I fix it.

Problem: When I plug in the power supply and then switch it on the computer starts running with all the fans and LEDs for about five seconds then shuts off. If the power button is pressed, whether on computer case or button on the motherboard the computer does not turn on. Video Link: [video="https://www.youtube.com/watch?v=UzvIHCO1gPg&feature=youtu.be"][/video]

We actually have two of these motherboards in the lab but the correctly working one is being used by one of our main computers. Here's a video of it working in the lab. [video="https://www.youtube.com/watch?v=_zucrumCIu4&feature=youtu.be"][/video]

Specs:
CPU: AMD A8-Series A8-6600K
Motherboard: Asus F2A85-V Pro
GPU: XFX AMD Radeon R7 260x 2GB
Hard Drive: 500GB Seagate
Power Supply: Corsair - CX 430W 80+ Bronze Certified Semi-Modular ATX Power Supply

 

[romirez]

If Power Button of PC Case is bad (shortcuted) - any mobo will start from PSU and will off in few secs like that.
So, check it -disconnect wires from PWRBTN and turn PSU ON.

 

[scollbusiness01]

If Power Button of PC Case is bad (shortcuted) - any mobo will start from PSU and will off in few secs like that.
So, check it -disconnect wires from PWRBTN and turn PSU ON.

Good idea but unfortunately it didn't work. Although, I tried the properly working motherboard in my case and it started doing the same thing (shutting off with a beep) but it would turn on when I would press the PWRBTN on the case or the Direct Key on the Mobo and then shut off.
I kinda got frustrated because I thought I just broke the good Motherboard but it kept coming up with a splash screen saying "no CPU Fan detected" "no keyboard detected" and then would shut off. I then attached and plugged in the CPU fan and it started working properly again, which just dug a deeper hole in my situation.