Pioneer PDR-L77 Service Manual page 52

PDR-L77
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6.4 ADJUSTMENT 1 (LASER DIODE POWER ADJUSTMENT)
CD-R CORE ASSY
TE
L 13942296513
VR164
RW ERASE
Fig. 4 Adjustment points
6.4.1 Playback Power Adjustment
Test Point
Pickup objective lens
Adjustment Point VR101 (PB. PW)
0.60 mW ± 0.05 mW
Adjustment Value
[Procedure]
(1) Check that "CD" is displayed on the FL display. If "CD-R" or "CD-RW" is displayed, press the ERASE button repeatedly until "CD" is
displayed.
(2) Press the RECORD button.
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(3) Press the REC MUTE button. The LED for confirmation of LD emission will light in red. The LD is emitting in this status.
(4) Turn VR101 clockwise until the adjustment value to be reached is obtained.
(5) Press the STOP button to shut off the LD.
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CN102
6
1
1 : RF
2 : VC
3 : MPP
4 : TE
5 : VC
6 : FE
VR141 VR163
RW BIAS R REC
VR161 VR162 VR101
RW REC R O.D. PB. PW
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8
CD-R overdrive
Playback power
Playback CD-R recording
Fig.5 Output power of the laser diode
Note 1 : Attach the remote sensor of the laser power meter to a
point angled away about 10 degrees against the pickup
lens and where the maximum power is detected, so that
there will be no light reflected onto the pickup.
Note 2 : When adjusting with VRs, first turn them completely
counter-clockwise and then adjust clockwise, so that the
value to be reached is not exceeded.
Note 3 : The wave length setting of the laser power meter is
assumed to be 780nm.
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DANGER – LASER RADIATION WHEN OPEN.
AVOID DIRECT EXPOSURE TO BEAM.
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CD-RW record power
CD-R record
power
CD-RW bias
power
CD-RW recording
CD-RW erase
power
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