Unplug the mic. If it stays keyed up, then you have a problem within the radio. If it un-keys, then the problem is in the microphone. If it is internal to the radio, take it to a competent technician. If the problem goes away when the mic is unplugged, then get a new microphone.
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Unplug the mic. If it stays keyed up, then you have a problem within the radio. If it un-keys, then the problem is in the microphone. If it is internal to the radio, take it to a competent technician. If the problem goes away when the mic is unplugged, then get a new microphone.