5.2 Maintenance of laser pickup5.3 Replacement of laser pickup
(1) Cleaning the pickup lens
Before you replace the pickup, please try to clean the lensTurn of the power switch and, disconnect the
with a alcohol soaked cotton swab.power cord.
(2) Life of the laser diode
When the life of the laser diode has expired, the following
symptoms will appear.
Replace the pickup with a normal one. (Refer
NOto "Pickup Removal" on the previous page)
Is RF outputReplace it.
0.9 0.22Vp-p?
Plug the power cord in, and turn the power on.
YESAt this time, check that the laser emits for
about 3 seconds and the objective lens moves
up and down.
O.K
Note: Do not observe the laser beam directly.
(3) The level of RF output (EFM output, amplitude of eye pat-
tern: pin5 of IC601) will be low.
(4) 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 laserPlay a disc.
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,Check the eye-pattern at 5pin of IC601.
and the laser pickup should be replaced. If the semi-fixed
resistor is adjusted while the pickup is functioning normally,
the laser pickup may be damaged due to excessive cur-
rent.Finish.
(No.MB004)1-25 |
ACEC
