Installed a new CPU cooler, computer keeps rebooting over and over again

[rng_esus]

I've just installed a new CPU cooler (Cooler Master Hyper 212 LED Turbo) after I was getting not-so-good idle (50-70 °C) and load (100+ °C) temperatures with the Intel stock cooler and my i7-3770. It should be noted that one of the pins on the 4 pin connector from one of the fans was missing. I don't think I put too much or too little thermal paste, and I believe I've installed everything correctly. So when I booted my system, both CPU cooler fans and the system was working (no display though) ...however after a few seconds, my PC shut down on its own and rebooted itself, it would keep on rebooting itself if I didn't turn off the power outlet as there was no way to turn it off even with the power button.

My specs
Motherboard: Gigabyte Z77P-D3
CPU: Intel Core i7-3770
Graphics card: MSI GeForce GTX 970
RAM: 8 GBs (Kingston)
Power supply: AeroCool KCAS 650M
Storage: 1 TB HDD (Western Digital),
500 GB HDD (also Western Digital)

I know that some of my parts are outdated and I have a cheap power supply with a bronze certification.

What I have already tried
- Reseating my RAM with multiple configurations
- Taking out the new CPU cooler (Hyper 212 LED Turbo) and replacing it with the old Intel stock cooler
- Taking out the CMOS battery from the motherboard and putting it back
- Unplugging and replugging my hard drives to see which ones are causing the problem
- Replaced my graphics card (MSI GeForce GTX 970) with an old graphics card (Sapphire Radeon HD 7750)

This issue has occurred a few months ago before I installed the new CPU cooler

None of the methods above worked, so are there any other solutions that I have not tried?

 

[Dark Lord of Tech]

I would also replace the PSU with a reliable make and model.