JVC KDG400
Service Manual

SECTION 5 TROUBLE SHOOTING
5.1 Feed section
Is the voltage output at IC541 pin 40 5v or 0V
NO

Is the wiring for IC541 pin 40 correct?

YES

Is 5V present at IC501 pins 3,12 and 21?
YES

NO

Check CD 8V.

YES

NO

Check the vicinity of IC541.
YES

Is 4V present at both sides of the feed motor?
YES

NO

Is 6V or 2V present at IC501 pins 4 and 5?
NO

Check the feed motor connection wiring.

Check the feed motor.

Check IC501.

5.2

Focus section
When the lens is moving:
NO

Check the circuits in the vicinity of IC501 pins 8 and 9.

4V
Does the S-search waveform appear at IC501 pins 8 and 9?

YES

YES

Check the pickup and its connections.

5.3

Spindle section

Is the disk rotated?
YES

NO

Is 4V present between IC501 pins 6 and 7?
YES

NO

Is 4V present at IC541 pin 41?
YES

NO

Check IC541.

Does the RF signal appear at IC521 pin 19?
YES NO NO

Check the spindle motor and its wiring. Check the circuits in the vicinity of IC521 pin 19 or the pickup.

Check the vicinity of IC501

Is the RF waveform at IC521 pin 19 distorted?
YES

Proceed to the Tracking section
5.4 Tracking section
When the disc is rotated at first:
Approx. 1.2V

NO

Check the circuits in the vicinity of IC501 pins 2 to 11.

NO

Check the pickup and its connections.

Is the tracking error signal output at IC521 pin 11?
YES

Check IC541.

(No.MA074)1-25