MDX-G1
5
CIRCUIT DESCRIPTION
1. The recording start addresses of IN, MID, and OUT are
described below.
IN
30H cluster
MID 300H cluster
OUT 700H cluster
2. An erasure prevention control is not detected in the test
mode. Be careful not to enter the continuous recording
mode using a disc containing the data that should not be
erased.
3. Do not record continuously for more than five minutes.
4. Take care that no vibration is applied during continuous
recording.
6. ELECTRICAL ADJUSTMENT
6-1 Precaution during confirmation of Laser
Diode emission
During adjustment, do not view the emission of a laser
diode from just above for confirmation. This may dam-
age your eyes.
6-2 Precaution on handling of Optical pick-up
(KMS-260B)
The laser diode in an optical pick-up is easy to be sub-
ject to electrostatic destruction. Therefore, solder-
bridge the laser tap on the flexible board when han-
dling the optical pick-up.
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 mea-
sures against electrostatic destruction. The flexible
board is cut easily. Handle the flexible board with care.
6-3 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.
2) In the test mode, perform the adjustment. After adjust-
ment 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 M
Ω
)
(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 moni-
tored on the oscilloscope. (VC and GND are short-circuit-
ed in this case.)
6-4 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 4-6.
BD board
IC7
D3
IC1, IC2, IC6
O
O
O
O
X
O
O
X
O
O
X
O
O
X
O
Pick-up
Flexible board
6-5 Offset Adjustment
No.
Key
Display/Function
1
4 ¢
Select [TEMP ADJU]
2 MD
6
[TEMP=xx (yy)]
(xx=compensation data, yy=setting temperature)
3
4 ¢
Input "yy" with present temp..
4 MD
6
[TEMP=
✽✽
SAVE] in writing data
[TEMP ADJU ST]
6-6 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
+
-
Laser
power meter
Digital
voltmeter
Objective lens of
optical pick up
TP2
TP1
X33
ADJUSTMENT
1. Laser Power Adjustment
No.
Key
Display/Function
1
4
¢
[LDPWR ADJU]
Load recordable disc
2
Load the disc and lazer on
[(a0.9mW) $xx] read power
(xx=power value)
4
3
EJECT
MD
6
Unload the disc and laser on
5 MD
6
[LDPWR CHECK]
6
1
¡
Move the pickup to check the laser power with
laser power meter sensor
7
4
¢
Adjust "xx" so that the power meter shows 0.9mW.
8 MD
6
[(a7.0mW) $xx] writing power
9
4
¢
Adjust "xx" so that the power meter shows 7.0mW.
This adjustment should be carried out in 15 secs.
10 MD
6
Laser power off
Display shows [LDPWR ADJUST] after [LDPWR<$xx]
to save the data in E2PROM
Start from No.2 if readjust.
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