1. Annual maintenance knowledge:

　　1. Clean the dust on the circuit board.

　　2. The electrolytic capacitor capacity in the circuit board is randomly checked, if the capacity of the electrolytic capacitor is found to be less than 20% of the nominal capacity, it should be replaced, and the general life of the electrolytic capacitor should be replaced for about ten years to ensure the working performance of the pcb.

　　3. For high-power devices coated with heat dissipation silicone grease, check whether the heat dissipation silicone grease is dry and solid. For dry and solid devices, remove the dry and solid heat dissipation silicone grease and apply new heat dissipation silicone grease to prevent the high-power devices in the circuit board from burning out due to poor heat dissipation.

　　2, seasonal maintenance:

　　1. Clean the dust on the circuit board every quarter, use the circuit board special cleaning solution for cleaning, after cleaning the dust above, dry the circuit board with a hair dryer.

　　2. Observe that the electronic components in the circuit have no traces of high temperature, and the electrolytic capacitor has no bulging leakage phenomenon, if any, it should be replaced.