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UX-A7DVD
3.3 Maintenance of DVD pickup
(1) Cleaning of pickup lens
a) Prior to changing the pickup, clean the pickup lens.
(2) Confirmation of the service life of laser diode when the ser-
vice life of the laser diode has been exhausted, the follow-
ing symptoms will appear.
a) The RF output (EFM output and eye pattern ampli-
tude) will become lower.
b) The drive current required for light emitting of laser di-
ode will be increased.
Confirm the service life according to the following flow chart:
Is the RF output
1.25
0.22VP-P?
YES
OK.
(3) Semi-solid state resistors on the APC P.C. board
The semi-solid state resistor on the APC P.C.board at-
tached to the pickup is used for adjusting the laser power.
Since these resistor should be adjusted in pair according to
the characteristics of the optical block, be sure not to touch
on the resistors.
Since the service life of the laser diode will be exhausted
when the laser power is low, it is necessary to change the
pickup. Meanwhile, do not pickup. Otherwise, the pickup
will be damaged due to over current.
1-40 (No.22013)
NO
Change the pickup
3.4 Procedures of changing the DVD pickup
The power switch is turned off,
and the power code is pulled out from the outlet.
Change the DVD pickup by referring
to "Removing the DVD pickup" in the
Disassembly Method.
The power code is inserted, and the power switch is
turned on. It is confirmed that the laser emits light
for about three seconds at that time, and object lens
moves vertically.
Completion the disc.
It is confirmed to be able to observe the shape of
waves of the eye pattern to TP602.
Completion of changing the DVD pickup.
Therefore, besure to perform not only adjustment and
operation of this system so carefully as not to directly
look at thelaser beam or touch on the body.
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