Pioneer AVIC-Z2/XU/UC Service Manual page 158

5
Symptoms in case of poor adjustment:
Caution: Avoid exposing your eyes to laser beams for a long time.
Preparation for adjustment: Clean both ends of the shafts.
Use brand new skew screws supplied with the service kit GXX1259.
Procedures:
1. Place the DVD mechanism module upside down.
To avoid the disc from being robbed when it is turned upside down, first put a coin of about 1.5 mm on the table,
then turn the disc upside down and set it so that the 1 in the figure comes to the point immediately above
the coin.
2. After replacing the pickup (by referring to the procedures of "Removing the Pickup."), roughly adjust the three
skew screws through visual check so that the pickup is mounted in parallel to the CRG chassis around the inner
and outer tacks.
3. Connect an oscilloscope as shown in the connecting diagram.
4. Turn on the power of the product. Load the test disc (GGV1018).
5. In the front-end test mode, set the disc type to DVD layer 1. Then, turn on the power. Move the pickup toward
the inner tracks.
6. Turn on the laser diodes.
7. With the focus servo closed, complete all automatic adjustments. Close the tracking servo, and then complete all
automatic adjustments.
8 Follow the next procedures, from 8-1 to 8-5, and adjust the (three) skew screws.
8-1 Move the pickup toward the inner track and turn the skew adjustment screw C so that the RF level of
oscilloscope becomes the maximum.
(Tangential adjustment at the inner track position: Adjust the flatness of the disc at the inner track position with
the adjustment screw C)
8-2 Move the pickup toward the outer track and turn the skew adjustment screw B so that the RF level becomes
the maximum.
(Tangential adjustment at the outer track position: Adjust the flatness of the disc at the outer track position with
the adjustment screw B)
8-3 Leave the pickup at the outer track position and turn the skew adjustment screws A and B in the same direction
alternately one quarter at a time (A•B•A•B •••) so that the RF level becomes the maximum.
(Radial adjustment at the outer track position: Keeping the flatness at the outer track position, adjust the flatness
of the whole disk with the adjustment screws A and B)
8-4 Move the pickup toward the inner track and turn the skew adjustment screw C so that the RF level becomes
the maximum.
(Tangential adjustment at the inner track position: Adjust the flatness of the disc at the inner track position with
the djustment screw C)
8-5 Repeat the steps from 8-2 to 8-4 three times, and adjust at the position where the RF level becomes the
maximum.
9. Turn off the power in the test mode. After confirming that the disc has stopped, eject the disc.
10. Adjust with a screw rock the shaft and skew adjustment screw to the same state as initial one.
Skew adj. screw
Prevent applied glue
from extending beyond this position.
5
6
Error efficiency deteriorated: 10
High jitter of the RF signal RF waveform deformed
Unstable operation in tracking closing and servo control
Apply glue
Shaft
1
AVIC-Z1/UC
6
7
-3 -4
(Optimum value: 10 or lower)
Skew adj. screw
Prevent applied glue
from extending beyond this position.
7
8
A
B
C
D
E
C
B
A
F
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