This phenomenon is usually the fault line drive transformer T502 pin cracks or line pipe Q501 due to breakdown.etRservice manual download site
     Open the case, careful observation with a magnifying glass, it was found T502 secondary S1, S2 pin solder cracks, is Weld. After re-welding power failure remains; then welded down pipe Q501 check their c, e pole has a breakdown. The line marked on the pipe circuit diagram model 2SD1541, but the actual use of models for the ASD1632. Direct substitution with 2SD1555, all the normal boot.etRservice manual download site