Sharp HT-DV30H Service Manual page 81

From 7-1 Page
Is SLED control signal output from pin 58 of IC1 to pin 23 of IC2?
Is SPIN control signal output from pin 57 of IC1 to pin 4 of IC2?
Is Tracking control signal output from pin 42 of IC1 to pin 26
of IC2?
Is focus control drive voltage output from pins 13 and 14 of IC2?
Is focus control drive voltage applied to the focus actuator
terminal? (Pin 23 and 24 of IC1)
Check connection of optical pickup cables.
If no abnormality is detected, replace the optical pickup
mechanism unit.
• "No Disc" is displayed during DVD playback (when CD is playable) ... When DVD laser does not light up.
Is control signal output from pin 18 of IC1?
Is voltage of 3.3V applied to emitter of Q9?
Is voltage of approx. 2.3 V supplied to pin 2 of CNP1?
Check connection of optical pickup cables.
If no abnormality is detected, replace optical pickup mechanism
unit.
• "No Disc" is displayed during CD playback (when DVD is playable) ... When CD laser does not light up.
Is control signal output from pin 19 of IC1?
Is voltage of 3.3V applied to the emitter of Q3?
Is voltage of approx. 1.9 V supplied to pin 6 of CNP1?
Check connection of optical pickup cables.
If no abnormality is detected, replace optical pickup mechanism
unit.
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Check SLED control signal line between IC1 and IC2
(Refer Figure 1)
No
Check SPIN control signal line between IC1 and IC2
(Refer Figure 1)
No
Check Tracking control signal line between IC1 and IC2
(Refer Figure 1)
No Is voltage of 5 V applied to pin 8, 19 of IC2.
No Check line between IC2 and focus actuator terminal.
No Check signal line between IC1 and Q9.
No Check 3.3V line.
No Check around Q9.
Note: The laser diode is easily damaged by static electricity.
Carefully check static electricity and electric leak of the measuring
instrument.
Check signal line between IC1 and Q3.
No
Check 3.3V line.
No
Check around Q3.
No
Note: The laser diode is easily damaged by static electricity.
Carefully check static electricity and electric leak of the measuring
instrument.
7 – 2
HT-DV30H