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Consider checking the wiring first, and then replace the bulb, if there is a problem with the wiring, replace it or burn.
You think, if it's a problem with the bulbs, you can't burn them at the same time.
It's a light bulb, and it may have been in bad contact, and a few twists will eliminate it.
If the lamp is broken or the electronic rectifier is broken, take it apart and check it, and replace it with another one if it is broken.
It should be in the shape of a bulb, and if you have a cover, first disassemble the cover, and directly unscrew it (counterclockwise) to buy a new replacement on it
Take off the edge of the utility knife, buy a new lamp and replace it with a plug in the back, don't wire.
Ventilation and ventilation turned on together? There is no such reason. These devices are wired according to the instructions.