The electronic ballast is rectified directly with the municipal electricity, then the half-bridge is reversed and the fluorescent tube is lit. It is not isolated from the electricity, like the hot bottom of the TV set, the circuit board is charged everywhere, the human body contact with the public line (ground wire) have the risk of electric shock, maintenance should pay special attention to personal safety. When power is added, do not touch any metal parts of the circuit board with your hands, especially without holding the circuit board with your hands. During the overhaul, remove the lamp, remove two circuit boards A and B from the plastic hood of the two ends of the lamp frame, and weld the four wiring 1-4 of the filament spring sheet, and weld it to the filament pins at both ends of the lamp in turn, and connect the switch SWI and the power plug on the mains. It is very necessary to connect the 5W1. During the repair found that not to connect the SW1, in the plug-in process, multiple damage to the electronic ballast, this is because the plugging process, often there will be a number of through, broken situation, which will produce a high tip pulse voltage breakdown vulnerable components.