Computer instantly restarts without warning

[BoldStep]

Recently my computer has started having a host of problems including audio (unrelated to this topic) and restarting without warning. This seems to happen randomly regardless whether it is running games or not and when it happens the screen goes black and restarts. The most recent one happened while just watching youtube. My computer is somewhat dusty but definitely not enough to cause something like this and its been dustier before and never caused this problem. I have a 650w psu so that is more than enough power for my computer, it isn't even that old. It is in a hot environment and can get quite noisy, but it has always been noisy anyways and seems to happen even when its at idle load. These are my temperatures after it restarted.

My tower actually once fell due to a trapped cable and the hard drive began to have problems after. I started hearing a grinding sound from it and (I don't know if its related) but when searching something on my browser it doesn't always go to that page, but just goes to the page I'm already at.
I am getting a new computer next month but I do want to hear what could be causing it.
These are my specs:
Motherboard: GA-78LMT-USB3
CPU: FX 6300 (with stock cooler)
Memory: 8 gb
GPU: EVGA GeForce GTX 960 SuperSC ACX 2.0+
PSU: SeaSonic G-650W 80Plus Gold Modular
OS: Windows 10 Professional

Thanks

 

[AniChatt]

Few suggestions,
1. Clean the pc with pressurized air properly by removing gpu and other cable mess.
2. Check whether all psu power cables are properly connected or not.
3. download hwinfo or similar and check temp or any other irregularity in the stats.
It may happen due to a faulty PSU as well check it in a different pc if possible