Sony Walkman MZ-R900 Service Manual page 18

MZ-R900
7) Select the manual mode of the test mode, and set item number
871 (see page 13).
Remote commander LCD display
871
:Adjusted value
[VOL+]
8) Adjust with the key (adjusted value up) or
key (adjusted value down) so that the adjusted value becomes
20.
9) Press the key to write the adjusted value.
X
10) Select the manual mode of the test mode, and set item number
872 (see page 13).
Remote commander LCD display
872
:Adjusted value
[VOL+]
11) Adjust with the key (adjusted value up) or
key (adjusted value down) so that the adjusted value becomes
39.
12) Press the X key to write the adjusted value.
Power Supply Manual Adjustment
• Adjustment sequence
Adjustment must be done with the following steps.
1. Vc PWM Duty (L) adjustment (item number: 762)
r
2. Vc PWM Duty (H) adjustment (item number: 763)
r
3. Vl PWM Duty adjustment (item number: 764)
• Setting method of power supply manual adjustment
1. Make sure that the power supply voltage is 3V.
2. Set the test mode (see page 12).
[VOL--]
3. Press the . or
mode.
Remote commander LCD display
000
[JOG LEVER $L% ]
4. Press the
on the remote commander.
[JOG LEVER $L% ]
(Pressing the
key on the remote commander causes the item number to be
switched to 762.)
18
[VOL--]
[VOL--]
key to activate the overall adjustment
[PLAYMODE]
r (down) key, or
[PLAYMODE]
(down) key, or
r
• Adjustment method of Vc PWM Duty (L)
(item number: 762)
Remote commander LCD display
762
: Adjusted value
1. Connect a digital voltmeter to the AP914 (VC) on the MAIN
board, and adjust
(voltage down) so that the voltage becomes 2.40
MAIN board
AP914 (VC)
AP912 (GND)
2. Press the key to write the adjusted value.
X
(The item number changes to 763 when
Adjustment and Connection Location: MAIN board
• Adjustment method of Vc PWM Duty (H)
(item number: 763)
Remote commander LCD display
763
: Adjusted value
1. Connect a digital voltmeter to the AP914 (VC) on the MAIN
board, and adjust
(voltage down) so that the voltage becomes 2.75
MAIN board
AP914 (VC)
AP912 (GND)
2. Press the key to write the adjusted value.
X
(The item number changes to 764 when
key
Adjustment and Connection Location: MAIN board
• Adjustment method of Vl PWM Duty
(item number: 764)
Remote commander LCD display
764
: Adjusted value
1. Connect a digital voltmeter to the AP915 (VL) on the MAIN
board, and adjust
(voltage down) so that the voltage becomes 2.30
MAIN board
AP915 (VL)
AP912 (GND)
[VOL +]
key (voltage up) or
digital
voltmeter
key is pressed)
X
(see page 19)
[VOL +]
key (voltage up) or
digital
voltmeter
key is pressed)
X
(see page 19)
[VOL +]
key (voltage up) or
digital
voltmeter
[VOL --]
key
+ 0.005
V.
– 0.01
[VOL --]
key
0.015 V.
[VOL --]
key
+ 0.005
V.
– 0.01