E3 is voltage measurement first, slightly lower than 1V, indicating protection circuit is likely to act. Midpoint of the l-channel measurement (output) voltage and found pointer multimeter quick left, indicating the high negative pressure. It can be seen that "failure" at the power amplifier. In the process of checking the power amplifier circuit, l-channel circuit board there is a blackened copper foil rupture,vdgservice manual download site
After analysis, learned that this piece of copper foil is Dianyuan's power supply line. The machine circuit board, which has four power amplifier tube installation location, but only the two power amplifier tubes (r, l-channel pair). Measurement of 2SC3280 between the legs of the l-channel power amplifier tube resistors, perceive a breakdown, and it paired tubes 2SA1301 not penetrate. Simply the amplifier tubes removed and burnt copper foil with a thick line of connectivity, power, the relay normally absorbs, on other circuits properly. Put on a pair of good power amplifier tube, "failed" excluded.vdgservice manual download site