Sharp DV-S2U Service Manual - Page 20

E56B0TS 1-8-1 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 5V line voltage normal? No Yes Is the voltage of secondary side normal? No FLOW CHART NO.2 The fuse blows out. Check the presence that the primary component is leaking or short then service it if defective. After servicing, replace the fuse. See FLOW CHART No.2 Check if there is any leak or shor-circuit on the primary circuit component? (Q1001, Q1003,T1001, D1001, D1002, D1004, D1005, D1011, C1003, C1005) Check each rectifying circuit of secondary circuit. Check the presence that the rectifying diode or circuit is shorted in each rectifying circuit of secondary side then service it if defective. FLOW CHART NO.3 When the output voltage fluctuates. Does the photo coupler circuit on the secondary No side operate normally? Yes Does the photo coupler circuit on the primary side No operate normally? Check the circuit and replace the parts. (IC1001, IC1006, D1048, D1015) Check the circuit and replace the parts. (IC1001, D1012, D1024) FLOW CHART NO.4 When buzz sound can be heard in the vicinity of the power circuit. Check if there is any short-circuit on the rectifying diode and the circuit in each rectifying circuit of the secondary side. (D1003, D1008, D1009, D1013, D1016, D1030, IC1002, Q1002, Q1004, Q1007, Q1011, Q1014) FLOW CHART NO.5 The fluorescent display tube does not light. No Is the voltage of 5V supplied to Pins(6, 24) of IC2001? Yes No Is the voltage of -24V supplied to Pin(15) of IC2001? Yes No Is there 500kHz oscillation to Pin(26) of IC2001? Yes No Check the signal lines of FP-DIN, FP-DOUT, FP-CLK, FP-STB of IC2001 and CN1001? Yes No Are the filament voltage applied between (1, 2) and (34, 35) of the fluorescent display tube? Also negative voltage applied between these pins and GND? Yes Replace the fluorescent display tube. FLOW CHART NO.6 The key operation is not functioning. Are the contact point and the installation state of the key switches(SW2011-2014, 2016, 2017) normal? Yes Is the control voltage normally supplied to No Pins(3, 4, 7, 8, 9, 10) of IC2001? Check the EV 5V line. Check the -FL (-24V) line. Check R2001, IC2001 and their periphery. Check or replace IC2001 and DVD Main CBA unit. Check or replace the power circuit, D1016, D1017 and R1042, and their periphery. Check the key switches (SW2011-2014, 2016, 2017), and their periphery circuit. TROUBLESHOOTING