Sharp DV-NC70U Service Manual - Page 44

DV-NC70U/C DV-NC72U 44 FLOW CHART NO.18 Capstan servo does not function. 1Only PB mode inoperative Are REC and/or PB mode inoperative? Check peripheral circuit of X701. YES NO Is there 14.3MHz oscillation at pins(37) and (38) of IC701? Check AC-MC connector and capstan FG signal line. NO YES Does the capstan FG signal appear at pin(67) of IC701? YES Check capstan motor unit and/or replace. Is there capstan AFC and APC at pins(31) and (33) of IC701? Does PB CTL signal appear at pin(76) of IC701 (TP204)? YES YES Is there capstan AFC and APC at pins(31) and (33) of IC701? YES Dose pin(29) of IC701 operate normally? NO NO Does AA-MH harness normally? NO Replace IC701. Replace AA-MH harness. Check 1. Check 2. YES NO YES YES Does A/C head operate normally? Readjust the A/C head height. 2Only REC mode inoperative NO Replace A/C head. Check peripheral circuit of C715~716 and R708. NO Is the V-SYNC signal (reference) at pin(50) of IC701? YES Is there REC CTL signal output at pins(74) and (75) of IC701? YES NO Replace IC701. NO FLOW CHART NO.19 Picture E-E does not appear. Is picture signal inputted into pins(28), (30) and NO (31) of IC201? YES 1 External input mode • Check the line between the rear video input terminal and pin(30) of IC201. • Check the line between the rear video input terminal and pin(28) of IC201. 2 U/V tuner mode Check the line between the pin(24) of TU101 and pin(31) of IC201. Is picture signal outputted to the pin(52) of IC201? YES Is picture signal inputted into the pin(49) of IC701? YES NO NO Is 5V applied to the pin(12) of IC201? YES NO Check the line between pin(52) of IC201 and pin(49) of IC701. Check the PC 5V line. Is picture signal outputted to the pin(47) of IC701 ? Are serial data and clock signal applied to the pins (63) and (62) of IC201? YES NO Is 5V applied to the pin(51) of IC701? NO Check the VDD line of IC701. NO Check the line between pins(62) and (63) of IC201 and pins(84) and (85) of IC701. NO Is picture signal outputted to the emitter of video output buffer (Q251)? YES Line output: NO Is there V-SYNC signal input at pin(5) of IC2003? YES NO Is there V-SYNC signal output at pin(2) of IC2003? YES Check the VIDEO OUT terminal (J1202) and the line between the pin(2) of IC2003 and the VIDEO OUT terminal (J1202). Check Q251 periphery. Check the line between the Q251 emitter and the pin(5) of IC2003. Is 5V applied to the pin(3) of IC2003? YES NO Check the PC 5V line. Is the pin(1) of IC2003 on "L" level? YES NO Replace IC2003. Check the DVD-(H) line.