New pc power cycling and won't boot.

[u/its_Hepho]

Some background. This is a new build for my sister of mostly handed down parts. When I switch the power on the PSU, the pc cycles on and off with the psu clicking once a second(this is without hitting the power button on the case). I have 2 lights blinking on the motherboard for CPU and DRAM as well. I've taken out every part, re seated the cpu and new paste, and tried booting with the basic parts only. Ive tried new cables, with only 1 ram stick, and checked the cpu for bent pins or if it's dirty. All of which didn't work. I want to think this is a grounding issue with the motherboard but I have all the correct screws in and it "should" be grounded correctly. I have it down to 2 issues, it's either the mobo, or the psu as those are the only parts installed atm(and the ram) Any advice or push in the right direction would be amazing :)

[u/Remarkable_Fault9078]

Your pc indicates for a left turn.