ADV-700
4
Note for Handling the Laser Pick-up
The protection for the damage of laser diode.
If you want to change the optical device unit from any other units, you must keep the following.
(1) It should be done at the desk already took measures the static electricity in care of removing the OPU's
(Optical device unit) connector cable.
(2) Workers should be put on the "Earth Band".
(3) It shold be done to add the solder to the short land to prevent the broken Laser diode before removing the
24P FFC cable.
(4) Don't touch OPU's connector parts carelessly.
Replacement of the Laser Pick-up (Traverse Unit)
Check the Iop (Laser drive current).
If the present Iop (current) value exceeds +50% of the initial value, replace the Traverse unit (Laser Pick-up) with a new
one.
LD2
LD1LD3LD4
When measureing Laser drive current (Iop), playback the discs (CD, DVD) described below, measure Iop for CD Laser and
DVD Laser by the test point (LD1 ~ LD4) on the DVD Main P.W.B.
Test Disc : DVD/DVDT-S01 or commercially available discs.
: CD/TCD-784 (manufactured by ALMEDIO INC) or commercially available discs.
Iop Measurement Method
DVD Main Unit foil side
LD2
LD1
1. DVD Laser current measurement
(1) Connect the oscilloscope to LD1 of test point
for GND side and LD2 of test point for signal
side.
(2) Playback the title 1 / chapter 1 of the DVD
Test Disc.
(3) Measure the voltage between LD1 and LD2,
calculate Iop by the formula as shown below.
Iop=
Measurement Voltage Value
39 (Resistance Value)
2. CD Laser current measurement
(1) Connect the oscilloscope to LD3 of test point
for GND side and LD4 of test point for signal
side.
(2) Playback the track 1 of the CD Test Disc.
(3) Measure the voltage between LD3 and LD4,
calculate Iop by the formula as shown below.
Iop=
Measurement Voltage Value
39 (Resistance Value)
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TEL 13942296513 QQ 376315150 892498299
TEL 13942296513 QQ 376315150 892498299
http://www.xiaoyu163.com
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