I removed the power amplifier and put the charged wireless microphone module on the iron plate. It should be short-circuited. It's no use installing a wireless microphone. Other functions of the power amplifier are normal, that is, these contacts at the back. I removed the power amplifier and put the charged wireless microphone module on the iron plate. It should be short-circuited. It's no use installing a wireless microphone. Other functions of the power amplifier are normal, except that these contacts at the back are short-circuited and difficult to repair. Generally, one or two components are fine. You'd better contact the manufacturer to buy a board with the same frequency after sale and replace it. I removed the power amplifier and put the wireless microphone module on the iron plate. There should be a short circuit. It's no use installing a wireless microphone. Other functions of the power amplifier are normal. If you suspect that there is something wrong with this circuit board, you can't repair it yourself. Take it to the store where you bought it and have it tested. Now this circuit board can't be repaired after amateur, so we can only find a manufacturer to change the receiving module .. Microphones must have the same frequency and quantity …