1. Power supply failure: check whether the socket has power and whether the wire connected to the power supply is normal. If the power supply is normal, the power module of the high-voltage board may be faulty.
2. Switch failure: check if the switch of the high voltage board is open or damaged. If the switch is damaged, the switch may need to be replaced.
3. Circuit failure: The circuitry on the high voltage board may be faulty, resulting in the voltage not being output properly. This may be caused by a damaged component on the board and the faulty component needs to be repaired or replaced.
4. Overload protection: The high voltage board may be equipped with an overload protection feature that shuts down the voltage when the load is too high to protect the circuitry and equipment. If the load is too large, try reducing the load or increasing the voltage output capability.
Please note that the above are only some of the possible causes, and the specific cause needs to be determined in conjunction with the actual situation. If none of the above solutions work, it is recommended to contact a professional repairer for further diagnosis and repair.