Every time the machine after startup to normal on 3 ~ 10 minutes, the longest can sometimes see 20 minutes, automatically enter the standby mode. At this time, double color power indicator light is red, light 2 s, 7 s out again, so the cycle. Shut off the power, and boot up again after about 10 s, repeat the above process, analysis, maintenance: this TV series machine core protection circuit is more complex, and is equipped with perfect over voltage, over current, loss of pressure protection. Sampling of various kinds of protection circuit voltage are eventually sent to the standby control transistor Q852 base. Q852 when in a state of protection of the base voltage of 0 V (normal is 0.6 V), so that the relay RL801 release, AC220V voltage is shut off, the main power to stop working, and the machine in standby protection condition. Rncservice manual download site
 Rncservice manual download site
Visual delicate yellow ceramics capacitors C55 (122/2 kv) and C559 402/2 (kv) surface has a slight tear, replacement after the two capacitance, fault is still. Then disconnect all kinds of protection circuit of commissioning respectively, fault has not ruled out. Rncservice manual download site
 Rncservice manual download site
After many times of trial found - a rule: every time the TV put on the tile floor after a night, the second day morning to get the workbench to commissioning, earlier failure occurs, and standby times increased. As the growth of the TV set in the workbench place time, watching the time also increased, and the standby times less, can no longer standby continuous normal watch three or four hours. This phenomenon shows that fault may be related to air humidity. This machine signal board adopts double sided PCB. The gap between the lines is, positive and negative and was full of holes. Will the machine on the circuit board on the dust clean after many times of commissioning, troubleshooting.Rncservice manual download site