Fault test line supply voltage fluctuations in 90v-115v, use the autotransformer to TV power supply, found that the voltage between 220v-250v, fault phenomenon is more obvious, first off overvoltage protection detection diode vd821 (8.2v regulator) and voltage amplifier vq821 (2sc2500) collector, the fault invariant; then short-circuit line flow detection of resistance of r476, the fault is still so; replacement of voltage stabilizing block vq87 (s1854) is invalid, then from the under voltage amplifier vq832 (2sa1015) is invalid. Not the incandescent lamp has been 100w/220v in c831 capacitor connected to accelerate the fault, fault attack is accelerated apparently, in the limit (over) flow resistance r838/839 (0.27 ω /1w) resistance in parallel to a 0.39 ω /2w, the fault is no longer present, repaiwYTservice manual download site