Motorola Gm3688 Service Manual Top

The GM3688 is known for a "squelch crash" at the end of a transmission. The manual’s "Signalling & Squelch" section covers how to adjust the Hysteresis and Attack/Decay times via the service software to eliminate the annoying pop.

Unlike older radios, the GM3688 has a microprocessor-controlled head. The manual explains the serial data bus between the front panel and the main board. If your buttons are unresponsive, the manual directs you to check the Flex cable connections and the 5V rail to the CPU. motorola gm3688 service manual top