Temperature Correction; Laser Power Check - Sony Mz-G750 Service Manual

MZ-G750/R700
1. Connect a digital voltmeter to the TP902 (VL) on the MAIN
[VOL +]
board, and adjust
(voltage down) so that the voltage becomes 2.30 ± 0.01 V.
MAIN board
TP902(VL)
TP912(GND)
2. When press the X key to write the adjusted value, LCD dis-
plays as follows and power supply manual adjustment has com-
pleted.
This set LCD display
ADJ OK
Adjustment and Connection Location: MAIN board

5-6. Temperature Correction

• Adjustment Method of temperature correction
1. Select the manual mode of test mode, and set the mode num-
ber 014 (see page 13).
This set LCD display
SetTmp
: Adjusted value
2. Measure the ambient temperature.
[VOL +] [VOL --]
3. Adjust with ,
(hexadecimal value) becomes the ambient temperature.
(Initial value: 14h = 20 °C, Adjusting range: 80h to 7fh (–128
°C to +127 °C)
4. Press the X key to write the adjusted value.

5-7. Laser Power Check

Connection :
Optical pick-up
objective lens
MAIN board
TP(+)
TP(–)
Checking Method :
1. Select the manual mode of test mode (see page 13), and set the
laser power adjusting mode (item number 010).
This set LCD display
Laser
20
[VOL --]
key (voltage up) or
digital
voltmeter
0 00
0 14
key so that the adjusted value
laser
power meter
digital voltmeter
0 10
2. Press the
.
key moves to the most inward track.
3. Open the cover and set the laser power meter on the objective
lens of the optical pick-up.
4. Press the key, and set the laser MO read adjustment mode
N
(item number 011).
This set LCD display
LrefPw
: Adjusted value
5. Check that the laser power meter reading is 0.81 ± 0.08 mW.
6. Check that the voltage both ends (TP (+) and TP (–)) of resistor
R521 at this time is below 44 mV.
7. Press the N key, and set the laser CD read adjustment
mode (item number 012).
This set LCD display
HrefPw
: Adjusted value
8. Check that the laser power meter reading is 0.97 ± 0.10 mW.
9. Check that the voltage both ends (TP (+) and TP (–)) of resistor
R521 at this time is below 44 mV.
10. Press the key, and set the laser MO write adjustment mode
N
(item number 013).
This set LCD display
WritPw
: Adjusted value
11. Check that the laser power meter reading is 4.95 ± 0.50 mW.
12. Check that the voltage both ends (TP (+) and TP (–)) of resistor
R521 at this time is below 80 mV.
13. Press the x key to quit the manual mode, and activate the
test mode (display check mode).
Checking and Connection Location: MAIN board
key continuously until the optical pick-up
0 11
0 12
0 13