Sharp DV-NC70U Service Manual - Page 49

FLOW CHART NO.6 The [No Disc] indication. (In case focus servo does not function.) Is the focus control signal outputted to the pin(115) No of IC3701? Yes Is the focus control signal from the pin(115) of No IC3701 inputted into the pin(23) of IC3704? Yes No Is the focus control drive voltage outputted from the pins(1) and (28) of IC3704? Yes Check the pin(118) of IC3701 DAC power source periphery circuit. If it is normal, replace IC3701. Check the focus control signal line between the IC3701 and IC3704. Check M 8V line. No Is 8V voltage applied to the pin(22) of IC3704? Yes Check the pin(21) of IC3704 and replace IC3704. FLOW CHART NO.8 Both picture and sound do not operate normally.(1) Set the disc on the disc tray. Yes Do you have loading done the disk by normality? No Yes No Is the level of RF signal which is outputted from pin(31) of IC3301 normal? Yes No Replace the Main PWB unit. Yes See FLOW CHART NO.9 and NO.10. Check the loading switch. Check for contamination of objective lens of optical pickup. Replace traverse chassis unit. DV-NC70U/C DV-NC72U 49 Is the focus control drive voltage applied to the No terminal of focus actuator? Yes Check the connection of optical pickup cable. If it is normal, replace the traverse chassis unit. Check the line between the IC3704 and the focus actuator. Check CN3301. FLOW CHART NO.7-1 The [No Disc] indication during DVD playback. (When the laserbeam does not light.) Is the control signal outputted from IC3301? No Check or replace IC3301. Yes No Is 5V voltage applied to the emitter of Q3304? Check the S 5V line. Yes Is approx. 2V applied to the pin(21) of the pickup No Check the line between the Q3301, Q3302 and terminal? (See note.) Q3304. Yes Check the connection of optical pickup cable. If it is normal, replace the traverse chassis unit. Note: Since the laser diode is very susceptible to static electricity, be careful of static electricity or electricity leak from the measuring equipment when confirming the voltage. FLOW CHART NO.7-2 The [No Disc] indication during CD playback. (When the laserbeam does not light.) Yes Is the control signal outputted from pin(4) of IC3301? No Yes No Is 5V voltage applied to the emitter of Q3303? Yes Is approx. 2V applied to the pin(3) of CN3301? No Yes Check the connection of optical pickup cable. If it is normal, replace the traverse chassis unit. Check or replace IC3301. Check the S 5V line. Check the line between the Q3301~Q3303. Note: Since the laser diode is very susceptible to static electricity, be careful of static electricity or electricity leak from the measuring equipment when confirming the voltage. FLOW CHART NO.9 Picture do not operate normally. Set the disc on the disc tray. Yes Are the video signals outputted to the pins of main unit connector CN3202? No CN3202 1pin S-Y CN3202 3pin CB CN3202 5pin S-C CN3202 7pin CR Yes Check the main unit. (IC3601, Q3201~Q3204 periphery circuit.) Check the PC 5V line. Are the video signals shown above inputted into the pins of IC2001? IC2001 2pin S-C IC2001 6pin S-Y IC2001 14pin CB IC2001 16pin CR Yes No Check between CN3202 and CN202. Are the video signals outputted to each pins of IC2001? IC2001 33pin S-C IC2001 31pin COMP IC2001 28pin S-Y IC2001 22pin CB IC2001 19pin CR No No Is 5V applied to the pins(1) and (13) of IC2001? Yes Are the V-MUTE lines at the pins(3) and (15) of No IC2001 on "H" level? Yes Replace IC2001. Check the V-MUTE line. *1 *2