The fault has not ruled out the power supply is not stable, the power load and super chips don't work properly. Uhuservice manual download site
 Uhuservice manual download site
Check the machine insurance, ac power supply adjustment pipe, line output are normal. Q450 operation output tube collector, in + B filtering electrolytic capacitor (2823 two ends dummy load, the electricity + B (130 v) normal voltage between 0-70-120-0 v change; switching power supply has been working, problems in the control and protection circuit. Uhuservice manual download site
 Uhuservice manual download site
 Uhuservice manual download site
From switching power supply output, output power measurement plug-in MCD02 (see figure 1), (1) STD standby power foot has 10 ~ 12 v output, and the standby indicator lights, rows, oscillation and CPU working voltage are provided by its, suitable to check the voltage by the PR804 (20 n / 1 w) current limiting RQ803 sc2331 (2) after 5 v voltage regulator circuit of voltage stability; To supply the cPu and the standby indicator lights, found 10 v voltage RQ803 collector, emitter voltage of 0 v. People between RQ803 emitter and to an external 5 v power supply; TV standby indicator light is normal, finally find out RQ803 b - e junction open circuit is damaged, change new after the fault disappear. Uhuservice manual download site
 Uhuservice manual download site
Maintenance of key point in the process of test data: IC801: TEA2260 7 external capacitance, standby normal voltage of 2.5 V, failure of 4 V. IC801: TEA2260 attending an external oscillation capacitance, standby voltage of 2.5 V, and the failure 7 V; RQ803 emitter: the normal value of 5 v, failure 0 v. Uhuservice manual download site
 Uhuservice manual download site
The normal type samsung TV and plugged in standby indicator lights that glow, this is a feature of it. Uhuservice manual download site
 Uhuservice manual download site
This is not a fault in switching power supply part, CPU power supply section on TV. C823 + B voltage changes easy to give a kind of power supply false fault, the result is the CPU does not work.Uhuservice manual download site