Problem Explanation：
In fact, the projector does not completely stop working when it is turned off. The internal power panel is still in working state. This standby state is not really a complete shutdown.
When the power board is working, the capacitance and inductance will have varying voltage and current, so the ceramic capacitor will have noise due to the piezoelectric effect, and the inductance and transformer will oscillate the coil and mechanism due to the internal magnetic field change, and will also give out noise.
This noise can only be optimized, not eradicated. As long as the AC power cord is plugged in, the power board is in working condition. Therefore, it is recommended that the projector be disconnected from the AC terminal when not in use.
In fact, the projector does not completely stop working when it is turned off. The internal power panel is still in working state. This standby state is not really a complete shutdown.
When the power board is working, the capacitance and inductance will have varying voltage and current, so the ceramic capacitor will have noise due to the piezoelectric effect, and the inductance and transformer will oscillate the coil and mechanism due to the internal magnetic field change, and will also give out noise.
This noise can only be optimized, not eradicated. As long as the AC power cord is plugged in, the power board is in working condition. Therefore, it is recommended that the projector be disconnected from the AC terminal when not in use.