Sony MZ-R900 service manual 871 V5num, 872 V5dat, Assy00, 762 Vc1PWM, VchPWM, Vl PWM

MZ-R900

7)Select the manual mode of the test mode, and set item number 871 (see page 13).

Remote commander LCD display

871 V5num **

**:Adjusted value

8)Adjust with the [VOL+] key (adjusted value up) or [VOL--]key (adjusted value down) so that the adjusted value becomes 20.

9)Press the X key to write the adjusted value.

10)Select the manual mode of the test mode, and set item number 872 (see page 13).

Remote commander LCD display

872 V5dat **

**:Adjusted value

11)Adjust with the [VOL+] key (adjusted value up) or [VOL--]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).

3.Press the . or [VOL--]key to activate the overall adjustment mode.

Remote commander LCD display

000 Assy00

4.Press the [JOG LEVER $L% r] (down) key, or [PLAYMODE] key on the remote commander.

(Pressing the [JOG LEVER $L% r] (down) key, or [PLAYMODE] key on the remote commander causes the item number to be switched to 762.)

•Adjustment method of Vc PWM Duty (L) (item number: 762)

Remote commander LCD display

762 Vc1PWM **

**: Adjusted value

1.Connect a digital voltmeter to the AP914 (VC) on the MAIN board, and adjust [VOL +] key (voltage up) or [VOL --]key (voltage down) so that the voltage becomes 2.40 +– 0.010.005 V.

digital voltmeter

MAIN board

AP914 (VC)

AP912 (GND)

2.Press the X key to write the adjusted value.

(The item number changes to 763 when X key is pressed)

Adjustment and Connection Location: MAIN board (see page 19)

•Adjustment method of Vc PWM Duty (H) (item number: 763)

Remote commander LCD display

763 VchPWM **

**: Adjusted value

1.Connect a digital voltmeter to the AP914 (VC) on the MAIN

board, and adjust [VOL +] key (voltage up) or [VOL --]key (voltage down) so that the voltage becomes 2.75 ± 0.015 V.

digital voltmeter

MAIN board

AP914 (VC)

AP912 (GND)

2.Press the X key to write the adjusted value.

(The item number changes to 764 when X key is pressed)

Adjustment and Connection Location: MAIN board (see page 19)

•Adjustment method of Vl PWM Duty (item number: 764)

Remote commander LCD display

764 Vl PWM **

**: Adjusted value

1.Connect a digital voltmeter to the AP915 (VL) on the MAIN board, and adjust [VOL +] key (voltage up) or [VOL --]key (voltage down) so that the voltage becomes 2.30 +– 0.010.005 V.

digital voltmeter

MAIN board

AP915 (VL)

AP912 (GND)

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