FS-SD990 / FS-SD770
FS-SD550
Maintenance of laser pickupReplacement of laser pickup
(1) Cleaning the pick up lens
Before you replace the pick up, please try to Turn off the power switch and,disconnect the
clean the lens with a alcohol soaked cotton power cord from the ac outlet.
swab.
(2) Life of the laser diode
When the life of the laser diode has expired,
Replace the pickup with a normal one.(Refer
the following symptoms will appear.
to "Pickup Removal" on the previous page)
1. The level of RF output (EFM output:amplitude
of eye pattern) will below.
Plug the power cord in,and turn the power on.
At this time,check that the laser emits for
Is the level ofabout 3seconds and the objective lens moves
NO
RFOUT underup and down.
Replace it.
1.25V 0.22Vp-p?Note: Do not observe the laser beam directly.
YES
Play a disc.
O.K
Check the eye-pattern at TP1.
Finish.
(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 is adjusted while the pickup is functioning normally,the laser pickup may be damaged
due to excessive current.
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ACEC
JVC
