For the past few months, my desktop has often failed to start when I press the power button. It eventually stopped turning on normally and would only start if I switched the power off, waited a few seconds, and then tried again. I recently changed both the case and the power supply, but the startup problem remains.
There is now a separate overheating issue. Whenever the computer does start, the CPU temperature keeps climbing within a few minutes, even when I am only sitting in the BIOS, until the system shuts down. I replaced the thermal paste a few weeks ago and added another case fan, but neither helped. The CPU is a Ryzen 7 7800X3D, cooled by a Forgeon Azoth 360 ARGB liquid cooler, with an RTX 4080. The cooler's protective sticker was removed, and the system originally worked normally for more than two years. What should I check first?
3 Answers
Since the temperature rises even in the BIOS, this is almost certainly a CPU cooling problem rather than Windows or a heavy workload. Check that the cooler block is firmly and evenly mounted, that the pump is connected to the correct header, and that the pump is actually running. With a 360mm liquid cooler, a failed pump, trapped air, blocked loop, or poor contact with the CPU can cause temperatures to climb rapidly. Carefully feel the tubes and radiator while the system is on, and check the pump speed in the BIOS if it is reported there. Avoid repeatedly running the PC until this is fixed.
Replacing thermal paste will not help if the cooler is not transferring heat or its pump has failed. Make sure the protective film is gone, use the correct AM5 mounting hardware, and confirm the cold plate sits flat. If the pump is silent or reports zero RPM, replace the cooler or test with a known-good air cooler. A cooler failure would explain the immediate overheating, but it would not necessarily explain the intermittent power-on behavior.
The startup fault may be a separate issue. Reseat the motherboard power connectors, CPU power connector, RAM, and graphics card, and check that no extra motherboard standoffs are shorting the board after the case change. You can also test the case power switch by briefly bridging the motherboard’s power-switch pins with a screwdriver. If that works reliably, the case switch or its wiring is faulty. If it still behaves inconsistently, the motherboard becomes a strong suspect.
The system originally worked for over two years, and I confirmed that the cooler’s protective film was removed. The CPU is definitely the part overheating, so I’ll check the pump and mounting before replacing more components.