SpekIT

I recently acquired an older gaming PC from a friend of mine. From what I know, it is possible that the CPU was overheating for a while due to a faulty AIO, though I have no way of knowing this for sure. The PC has a boot loop problem when turning on. Nothing appears on the screen after pressing the power button. The lights will turn on and the fans will start up for a couple seconds, then turn off and back on again. The computer will do this for a seemingly random amount of time until it will make it past the boot loop issue. From then on, as long as the computer remains on, there are no problems. I have tested a new power supply, ram, and motherboard so I am fairly confident that it is in fact the CPU (I have been testing with a hyper 212 evo since I am unsure of the AIO). I guess what i'm wondering is if there is anything I can do to possible fix this issue and if there is any easy way for me to test the AIO. An suggestions would be greatly appreciated. Computer Specs: I7-4790k Asetek 550LC 120mm (Hyper 212 Evo during testing) Gigabyte Z97-D3H ADATA XPG 16 GB kit Corsair CX600M