Still not fixed. At present, the measured power supply voltage is normal, when I remove the acquisition board, both fans on the side of the oscilloscope rotate, but after the acquisition board is installed, only one fan rotates. Looking at the maintenance manual, it says that the acquaintion board will detect the temperature and then adjust the speed of the fan, who knows where the circuit for detecting and adjusting the fan is?
I saw that there is a place marked with sense on the acquisition board, it seems to be C100, and the two ends of the measurement are in a short-circuit state, I wonder if this is normal?