Question Random Shutdown & Multiple Attemps to Start up

[HiggsPrime]

I am not sure if this is the right forum to ask question. this is new TH interface, before it was just post and add tags. Last i visited was 2014.

Anyways, I have this PC for about 5 yrs now and sometimes it gives me the following problems:

1. Random PC shutdown. Just writing this post I had to start 4 times. This occurs twice after 4 normal working PC days. and then its back to normal.

2. occasionally, when i press start button, there is light from Mobo and all fans are running but no display, so I have to unplug from mains and start several times until i get the display.

Computer Specs:
CPU- FX 8320
RAM- 8GB 1600Mhz(2x4GB)
MoBo- M5A99X Rev.2,
GPU- r9 270X 2GB (used),
Storage: 128SSD (OS Win10), HDD 1TB Seagate
PowerSU 650W PowerCool.
CPU Cooler: Cooler Master Hyper EVO

Picture of the PC

What may the problem ?

 

[HiggsPrime]

I have read the Mobo Manual and test and trialed alot. the following have been done

1. GPU was place to lower PCIx16, the PC restarts every 5-10mins.

2. updated BIOS via USB BIOS succesfuly (followed manual)

3. VGA Red light indicator, meaning problem i the GPU.

4. Turning on TPU does not help.

Just yesterday I played CS:GO, BF4, and Backbone and other, and the PC was on for 6hrs non-stop. I duno why it happened, it maybe because of second hand. Also found out that 8GB ram of 1600 is not listed in supported list given Asus. its just its voltage rating is matched i.e. 9-9-2.

In conclusion, i think the GPU is damaged since VGA Red lights popsup and the PC restarts several times when slotted to other PCI.

Or is there any other problem I am missing ?