JVC KD-G227 Schematic Diagrams page 42

5.3 Spindle section
Is the disk rotated?
NO
Is the voltage output at
pin 6 and pin 7 of IC501?
NO
Is the voltage input at pin
17 of IC501?
NO
Is the voltage output at
pin 5 of IC521?
NO
Is the power supply
present at pin 37,
pin 49, pin 53, pin 56
and pin 72 of IC521?
NO
Check the connections
of CD8V power supply.
5.4 Tracking section
1-18 (No.MA236)
YES
Does the RF signal appear
at pin 39 of IC521?
YES
Check the spindle motor
and its wiring.
Is the power supply
YES
present at pin 3, pin 12
and pin 21 of IC501?
NO
Check the connections
of CD8V power supply.
Check the connections
YES
between IC501 and
IC521.
YES
Check IC521.
When the disc is rotated
at first:
Approx. 1.2V
Is the tracking error
signal output at pin 26
of IC521?
NO
Check the pickup and
its connections.
YES
Is the RF waveform at
pin 39 of IC521 distorted?
NO NO
Check the circuits in
the vicinity of IC521
or the pickup.
YES
Check IC501.
Replace IC521 or repair
YES
the malfunction
connection point
YES
Proceed to the Tracking
section