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RXD-M33/M33MD
When removing the flexible board from the connector,
make a solder bridge in advance, then remove the board.
Be careful not to remove the solder bridge before
inserting the connector. Moreover, take careful
measures against electrostatic destruction. The flexible
board is cut easily. Handle the flexible board with care.
Pick-up
8-3 Precaution during adjustment
1) Perform the adjustment and confirmation marked with "O"
in the order shown in the table when the parts below are
replaced.
Optical
pick-up
1.Temperature compen-
sation offset adjustment
2.Laser power adjustment
3.Traverse adjustment
4.Focus bias adjustment
5.Error rate confirmation
2) In the test mode, perform the adjustment. After
adjustment is completed, cancel the test mode.
3) Perform the adjustment in the order described.
4) Use the following tools and measurement equipment.
• CD test disc TGYS-1
• Laser power meter
• Oscilloscope (with bandwidth of more than 40 MΩ)
(Calibrate the probe before measurement.)
• Digital voltmeter
• Thermometer
5) Take care that VC and GND (ground) are not connected
on the oscilloscope when two or more signals are
monitored on the oscilloscope. (VC and GND are short-
circuited in this case.)
8-4 Creating the recordable continuous recording
disc
This disc is used for focus bias adjustment and error rate
confirmation. How to create the recordable continuous
recording disc is 3-8.
8-5 Offset Adjustment
No.
Key
1 Volume/multi-control Select [TEMP ADJU]
2 PLAY
[TEMP=xx (yy)]
(xx=compensation data, yy=setting temperature)
3 Volume/multi-control Input "yy" with present temp..
4 PLAY
[TEMP=✽✽SA]
[TEMP ADJU] in writing data
CIRCUIT DESCRIPTION
Flexible board
Laser tap
BD board
IC7
D3
IC1,IC2,IC6
X
O
O
O
O
O
X
O
O
O
X
O
O
O
X
O
O
O
X
O
Display/Function
8-6 Laser Power Check and Adjustment
Laser power setting in playback and recording modes.
Preparation
1. Remove the MD mechanism from the unit.
2. Connect the digital voltmeter to TP1 and TP2 on X33
pcb.
3. Remove the top plate from traverse unit.
4. Remove the magnetic head.
5. Remount the MD mechanism to the unit
Objective lens of
optical pick up
X33
ADJUSTMENT
TP2
TP1
1. Laser Power Adjustment
No.
Key
1 Volume/
[LDPWR ADJU]
multi-control
Load recordable disc
2
Load the disc and lazer on
PLAY
a 0.9mW) $xx] read power
(xx=power value)
3 EJECT
Unload the disc and laser on
4 4/¢
Move the pickup to check the laser power with
laser power meter sensor
5 Volume/
multi-control Adjust "xx" so that the power meter shows 0.9mW.
6 PLAY
a 7.0mW) $xx] writing power
7 Volume/
Adjust "xx" so that the power meter shows 7.0mW.
multi-control
This adjustment should be carried out in 15 secs.
8 PLAY
Laser power off
Display shows [LDPWR ADJU] after [LDPWR<$xx]
to save the data in E2PROM
Start from No.2 if readjust.
2. Laser Power Check
No.
Key
1 Volume/multi-control [LDPWR CHEC]
2 PLAY
c 0.9mW) $xx]
(xx=0.85 to 0.95mW)
3 PLAY
c 7.0mW) $xx]
Laser power meter: 7.0±1.0mW✽
VOM:optical pickup indication value ±10%✽
(optical pick-up label)
KMS
27x40
B0825
In this case, lop = 82.5 mA
lop(mA) = Reading of digital voltmeter(mV)/1(Ω)
8-7 EF Balance(Traverse Adjustment)
Connection :
X33
ADJUSTMENT
TE1
VC
Laser
power meter
Digital
voltmeter
+
-
Display/Function
Display/Function
260B
Oscilloscope
+
-
V: 0.5V/div H: 10ms/div
INPUT: DC mode
11
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