Does the system "lock-up" when your in the system bios? Boot the PC & enter the bios setup, let the pc sit there for @ least 5-10 Min.
If the system locks up?
it's either a heat problem witht the CPU
Or power problem. (Check the power supply voltages & all cable connections)
If @ all possible, find another CPU to test the system with.
If the system will operate properly in the system bios, but locks up soon after exiting the bios.
It's probably a RAM issue. Change memory slots & or DIMMs if possible.
LMK how things turn out.