The failure phenomenon, the machine can only shut off not plug in; If power supply can be connected, the machine can work normally. A preliminary judgment fault in the control circuit of the switch power supply. In the condition of the power switch off with a model 500 multimeter black pens and grounding and red pens and monitoring the electricity control transistor Q6001 the base for high level 13 v, connect the power switch, Q6001 base immediately from high level 13 v to 12.3, that has been added to the control signal voltage electricity Q6001 base. Further examination QR6003 collector voltage of 0 v (normal in power off state for high level 13 v, when electricity is low level 0 v). Pop-up battery check QR6003 collector in the right way to resistance is zero, from circuit boards welding under QR6003 examination revealed its c - e electrode has broken down. After replacing QR6003 (UN5213), machine work back to normal.zDDservice manual download site