This machine in normal watch suddenly "cob" in 3 without downtime. Light is in the second boot instantaneously from orange, and after a flash of green light in turn to orange light, and relay have off again to release the action, press the standby button on the remote control can't boot. 3g5service manual download site
 3g5service manual download site
Doubt protective circuit. From the power system protection circuit principle, caused a IC801 internal overvoltage protection circuit of control factors are: 1. The way of doubler rectifier switch circuit element, make C818 extreme of dc voltage is too high; 2. Sampling overvoltage protection circuit partial pressure resistance R816, R817, R818 metamorphism, make ends R818 sampling voltage caused from protection circuit formed by wrongly accused; 3. The voltage regulator tube D820 spoiled or Q803 beam electrode leakage that misoperation over-voltage protection circuit. For narrowing the scope of the fault, first measure SCR Q801 each arc resistance, not found the problem; Boot Q801 control voltage measurement, whose hands instantly obvious swing, a voice relay release at the same time, measuring the voltage of ov, the judgment is Q801 get abnormal trigger voltage control cabinet, to make it in the conduction state, rectifier filter circuit into a doubler rectifier, caused the doubler rectifier protection action, the fault should be out in the automatic switching control circuit. Ordinal check D817, Q854, D815, Q853, D816. R822. R823 and other components, found Q853 c and e very open, D815 circuit. Replace Q853 sc1685 (2) and D815 (regulated value of 7.5 V), troubleshooting.3g5service manual download site