Sharp DV-SL90UM Service Manual - Page 17

TROUBLESHOOTING FLOW CHART NO.1 The power cannot be turned on. Is the fuse normal? No Yes Is normal state restored when once unplugged No power cord is plugged again after several seconds? Yes Is the EV +3.3V line voltage normal? No Yes Check each rectifying circuit of the secondary circuit and service it if defective. FLOW CHART NO.2 The fuse blows out. See FLOW CHART No.2 Check if there is any leak or short-circuiting on the primary circuit component, and service it if defective. (Q1001, Q1003, Q1008, T1001, D1001, D1002, D1004, D1005, D1011, C1003, C1005) Check the presence that the primary component is leaking or shorted and service it if defective. Check the presence that the rectifying diode or circuit is shorted in each rectifying circuit of secondary side, and service it if defective. After servicing, replace the fuse. FLOW CHART NO.3 When the output voltage fluctuates. Does the photo coupler circuit on the secondary No side operate normally? Yes Check IC1001, D1012, D1024 and their periphery, and service it if defective. Check IC1001, IC1006, D1048 and their periphery, and service it if defective. FLOW CHART NO.4 When buzz sound can be heard in the vicinity of power circuit. Check if there is any short-circuit on the rectifying diode and the circuit in each rectifying circuit of the secondary side, and service it if defective. (D1003, D1006, D1008, D1016, D1030, IC1002, Q1002, Q1004, Q1005, Q1011) FLOW CHART NO.5 -FL is not outputted. Is approximately -23V voltage supplied to the No anode of D1003? Yes Check if there is any leak or short-circuit on the loaded circuit, and service it if defective. Check D1003 and periphery circuit, and service it if defective. 1-8-1 E592ATS