The power indicator feebly on the immediately after put out. btHservice manual download site
 btHservice manual download site
Measurement of main power supply outputs of all stripes, has weak voltage in boot instantaneously, after becoming OV. According to the case 1 train of thought for inspection, found no problem. Can be the load? Conventional measuring the output of no short circuit phenomenon. Because the line output stage is one of the largest load switch power supply, so along a 50 v. When the check to the secondary power supply (length, related circuit diagram escapes), found that the boost diode D401 end of the secondary power supply open welding, also found that the secondary power switch tube Q402 (IRF630) D - S between offers very little resistance. After the repair welding, replace a IRF630 new tube, switch on again, troubleshooting. btHservice manual download site
 btHservice manual download site
 btHservice manual download site
D401 sealing-off caused the secondary power supply voltage sampling voltage disappeared, so that the secondary power supply is out of control, burned the secondary power supply pipe Q4020 Q402 damage caused by 50 v output over-current, causing IC601 over-current protection, shut down output.btHservice manual download site