Panasonic SA-VK81DGCS Service Manual page 22

SA-VK81DGCS / SA-VK81DGCP
While press and hold "STOP" on main unit , press "Display" button on the remote controller. Unit display laser current on FL.
From the reading of display, you can judge if laser diode is damaged or not.
Reading on the right side should be less than 70. If reading is more than 70, laser is damaged.
How to confirm if Optical Pickup is OK
Confirmation 1
1. Confirmation of jitter value with test disc. (Refer below for how to check jitter)
2. Lens cleaning.
3. Reconfirm jitter value.
4. Perform tile adjustment. (Refer to tilt adjustment)
5. Reconfirm jitter value. (To confirm jitter value, while pressing "STOP" on main unit and "5" on remote controller.)
Unit display jitter value on FL.
Confirmation 2
If servo is very unstable due to optical error and you cannot confirm jitter value, clean the lens and check appearance of pick
up unit (cutting coil of actuator, etc), then check circuitry.
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