4 X Becker AR3201 VHF Transceiver

PLEASE READ: 4 x BECKER AR3201 as is. I tested all four radios with a dynamic mic with the following observation: 1: Turns on, receives and transmits but mic stops working after about 1 minute 2: turns on, receives and transmits but receive speaker output is not amplified (very quiet). 3: does not turn on 4: does not turn on Selling as spare or parts.