SHARP MDR3H
Service Manual

MD-R3H
� Disc motor fails to run
Does waveform appear on the pins 24 and 25 of IC1201 in the TEST mode focus gain coarse adjustment step? Yes Does waveform appear on the pins 34 and 35 of IC1601, pins 1 and 2 of CNP1603? Yes Replace the completed disc motor. Check soldering joint of PWB of completed IC1601 and CNP1601 disc motor. No Check soldering joint and parts of pins 24 and 25 of IC1201, and peripheral circuit.

No

� Tracking servo failure
Does waveform appear on the pins 8 and 9 of IC1601, and pins 1 and 3 of CNS1101 in the TEST mode focus gain adjustment step? Yes Replace the optical pickup. No Check the soldering joint of pins 20 and 21 of IC1201, IC1601, IC1601, CNS1101.

� Slide servo failure
Does the pickup move to external and internal periphery when the or button is pressed in the TEST mode? No Is there any change on the pins 22 and 23 of IC1201 when the or button is pressed? Check the waveform on the pins 22 and 23 of IC1201, check the peripheral parts and soldering joint. Yes Check the waveform on the pins 22 and 23 of IC1201, check the peripheral parts and soldering joint.

No

Yes Is there any change on the pins 28 and 29 of IC1601, and the pins 1 and 2 of CNP1602 when the or button is pressed? Yes Does voltage on the positive and negative terminals of slide motor change when the or button is pressed? Yes Replace the slide motor. Check the soldering joint connected to the slide motor to see whether there is wire breakage. Check the soldering joint of IC1601 and CNP1602.

No

No

� 70 �