Replace the Power Supply Unit with one certified for Pentium 4 systems.
- The ATX specification has changed a lot since then, and some newer PSUs will not work correctly with that old hardware any more.
It sounds like the PSU is as old as the rest of the system, in which case it's probably full of dust and nowhere near as effective as it was when it was brand new.
Reason for system shutdown is to prevent more damage to hardware. Solution:buy a new heatsink with fan with thermal paste ,supported for p4.install the new processor cooler buyed. change the cmos battery.