Originally Posted by spirittoo
the cpu fan was loose
Please explain in more detail.
What exactly was loose? Was the fan loose where it mounts to the heat sink? Or was the entire heatsink fan (HSF) assembly loose where it mounts to the motherboard on top of the CPU? Or was the fan header (fan power connector) loose?
If the fan was not securely attached to the heatsink, then I don't see how that would prevent it from booting either. But do note on most heat sinks, the fan mounts by the screws "cutting" groves into the heatsink metal. And when the screws are backed out, tiny, highly conductive metal filings can come loose and fall onto the motherboard. You can see where I'm going with that!
If the fan's power connector had come loose, the normal default is the motherboard would fail to pass POST (power on self test) and would immediately shut down upon boot.
If the entire HSF was loose and not properly mounted on top of the CPU, then the CPU could easily go from cold to overheated in just a few clock cycles. And with a CPU running at 3 billion+ clock cycles per second, that would be almost immediately upon boot too. When a CPU overheats, it will (or should, if not faulty) immediately shutdown as a self-preservation action.
But also, if the entire HSF came loose, that means the cured bond of the TIM (thermal interface material) broke. And that's bad and you need to stop using your computer immediately because you should never, as in NEVER EVER reuse TIM if the cured bond has been broken.
If that is what happened, you need to unplug the computer from the wall, touch bare metal of the case interior, remove the entire heatsink fan assembly, thoroughly clean the two mating surfaces (I use 91% Isopropyl alcohol), then apply a thin
, fresh new layer of TIM. And remember, the best transfer of heat occurs with direct metal-to-metal contact of the mating surfaces. The purpose of TIM is to push out any insulating air trapped in the microscopic pits and valley of those mating surfaces. Any excess TIM is in the way and counterproductive to the most efficient transfer of heat. So you need to apply it in as thin a layer as possible, but still have complete coverage of the die surface.