From the failure phenomenon analysis, fault circuit may be P plate. Boot check, found that the damage of insurance. Further examination, found Q424 has breakdown. Due to Q424 and Q423 pulse width control signal from the P6 panel, carefully check the P6 panel, the damaged components has not been found, mount Q424 and insurance, boot normally. Q424 is in the grid for 110, through - the switch on the P6 panel S701 control to work, it can be removed when emergency.