A4000 slows down or crashes, boards or drives overheat. Check that airflow
isn't restricted by cables, that the fan or heatsink on the processor isn't
blocked and is attached solidly to the chip, and that the fan
is installed properly, so it blows hot air out the back of the power supply.
Overheating can cause seemingly unrelated problems with disk drives or
expansion boards, cause connectors to work loose, and reduce the lifespan
of silicon components.