Motorola Gp3188 Service Manual ❲8K 2025❳

The schematic shows that the reset circuit is driven by a TL7705 reset IC (or equivalent). If its output is stuck low, replace it. The parts list gives the Motorola part number: 5109626Z02.

Confirm the battery is charged (>7.0V on DMM). Check battery contacts for corrosion. If OK, proceed. motorola gp3188 service manual

Using a DMM on TP4: if 0V, suspect shorted capacitor C404 (100nF decoupling). If voltage is present but radio is dead, check the microprocessor reset line: pin 7 of U404 (68HC11) must go high (+3.3V) within 10ms of power-on. The schematic shows that the reset circuit is