+ B voltage of the first test, only 63V, and then measuring the CPU 26 foot pole shot and Q501, are low, indicating that the machine is already protected, and in the standby state. After disconnecting the R1143, the fault persists, the protection of the state failed to lift, it can be judged, the failure is not due to its remote control system, but the protection circuit caused.zjmservice manual download site

     In order to ascertain the exact location of the fault, using the circuit method to check, first disconnect the D456, the fault persists. Recovery D456, then disconnect the D530, protection status has not been lifted. Recovery D530, then they disconnect D752, boot, Q501 emitter goes high protection status lifted, but this time there is still no grating, indicating that the line output circuit failure. Measuring the output pipe collector voltage, close to 0V, the output pipe collector for the power supply circuit, it was discovered R758 circuit. 10W is a resistor R758, and so the resistance is blown power, the line output stage described serious short circuit exists, the output stage of the inspection line, the output pipe breakdown found. Line output tube and R758 will be replaced, troubleshooting.zjmservice manual download site