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Maintenance of laser pickup
(1) Cleaning the pick up lens
Before you replace the pick up, please
try to clean the lens with a alcohol
soaked cotton swab.
(2) Life of the laser diode
When the life of the laser diode has
expired, the following symptoms will
appear.
1. The level of RF output (EFM output: ampli
tude of eye pattern) will below.
(3) Semi-fixed resistor on the APC PC board
The semi-fixed resistor on the APC printed circuit board which is attached to the pickup is used to adjust the laser
power. Since this adjustment should be performed to match the characteristics of the whole optical block, do not
touch the semi-fixed resistor.
If the laser power is lower than the specified value, the laser diode is almost worn out, and the laser pickup should
be replaced.
If the semi-fixed resistor would be adjusted when the pickup operates normally, the laser pickup may be damaged
due to excessive current.
Replacement of laser pickup
1-21
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