During the sound reinforcement process, a pair of speakers suddenly disappeared, most of which is because the power amplifier on the output channel is overloaded, and the fast-melting fuse is blown. In this case, the fast-melting fuse of the same capacity is replaced, and the input signal of the power amplifier is reduced. Flat, you can resume normal operation. If the speaker is still silent after replacing the fuse, do not check the front device for any signal. Use the jumper method, that is, skip the previous device and insert the input signal of the previous device into the input end of the power amplifier. If it is still silent, the power supply of the power amplifier may be damaged or the power of the two channels may be burned out. Ensure that the sound reinforcement continues, and the power amplifier should be replaced as soon as possible. It is unlikely that two speakers will burn at the same time...