Ursprünglicher Beitrag von: Mike Kay ,
With the speaker side down, set the radio on a flat surface. Remove the microphone plug from the radio. Look at the socket the mike plug came out of. You will see a four pin connection. Look closely at the four pins. One of them has a small bump or notch near it. To the left of that notch is the ground pin. To the right of that notch is the receive pin. Above the ground pin is the mike pin. Above the receive pin is the transmit pin. With the radio turned on and the mike removed, take a small horseshoe shaped piece of wire and touch one end of it to the ground pin and the other end to the transmit pin. This will key the transmitter. If the needle on the meter does not move, you likely have a blown final. If the needle does move, you have a bad microphone or blown audio output IC.