JVC XV-DDV1SL Service Manual page 22

4.7.2 Preparation for adjustment
(1) See the disassembly procedure, and remove the mechanism assembly from the main body.
(2) Attach the three studs to the mechanism assembly.
(3) Remove the servo control board attached to the mechanism assembly.
(If you disconnect the wires connected to the servo control board, connect them again.)
(4) Be careful of the direction at the time of attaching a relay board in each substrate, and the direction when inserting an extended
cord in each board enough, and connect, respectively.
Servo control board
Relay board
Extended code connection state
4.7.3 Adjustment
(1) Set the unit test mode.
(2) Press the "SET UP" key of the remote controller three times, and the FL display is displayed "CHECK".
(3) Insert a test disc (VT-501), and press the numeric key "1" of the remote controller for automatic adjustment.
(4) After a few seconds, press the numeric key "6" of the remote controller. Then, the FL display displays a jitter value.
(5) Turn the adjustment screws on the underside of the traverse mechanism with phillips screw driver the maximum jitter value is
displayed on the FL display. (In this model, a bigger jitter value means a better result.)
NOTE:
• Reference values to judge whether the jitter is allowable or not are displayed, instead of actual jitter values.
• Please be sure to perform "all-initialization" and "optimization adjustment of front end parameter" after adjusting.
Screw a
Disc insertion part
1-22 (No.XA010)
Front side
Relay board
FL Display (Example)
0 7 8 1
Jitter value
Screw b
Screw c
Relay board Relay board
Main board
Installation state
< POINT >
Turn the adjustment screws a and b to the same
angle in the right direction. And turn the adjustment
screws a and b to the same angle in the left
direction. Then, turn the screws a and b in either the
right or the left direction to increase the number of
jitter. Don't turn the adjustment screw c.