1. If the whole no light without standby indicator has been light, then focus on examination of the + 12V formation circuit and load and its protection circuit C870, Q8sl and other components; standby indicator lights flashing after often bright, need to focus on examination of the main switch current and load T501, Q50l etc.; if the remote control shutdown of machine failure or abnormal map light sound and the standby indicator lights bright and dark twinkling changes, then focus on examination of the standby power supply and its control circuit.

. if "standby" indicator light does not shine, and switch transformer "squeak" sound, Emirates first detection output tube Q50l collector has no voltage 113V to narrow the scope of failure, if there is no 113V is key check the line output circuit whether existing unsoldering or open circuit fault; if Q50l C very normal working voltage and the R519 good, and IC601 (42) pin voltage below 1V, then can be certain fault is due to the second set of circuit protection action caused by.

At this time, in turn desoldering R454 and r420 and D502, d520, D522 and so on element after detection IC601 (42) of the pin voltage can recover to around 9V to determine which causes circuit protection action; if the disconnection of the sampling control element IC601 (42) pin voltage is still not restored normal, IC601 (42) pin voltage are detected after the unsoldering R536, if at this time to the foot of the IC601 voltage normal (9V), is to focus on examination of the protection circuit element q503, Q504, C580 etc., if at this time IC601 (6) feet below 1V, is to focus on examination of IC601.