Sony NWZ-X1051 service manual Judgment From The Test Mode, Judgment from the voltage measurement

Note: Refer to page 27 for the schematic diagram. Refer to page 28 for the printed wiring boards.

METHOD OF JUDGING RIGHT AND WRONG OF PARTS RELATED TO SWITCH

In this set, only a part of parts that relate to the switch are supplied. Exchange the entire mounted board when parts that do not corre- spond to it are defective.

The right and wrong of the switch can be judged by the following two methods.

1. Judgment From The Test Mode

Judge the right and wrong of the switch referring to “4-4-2. Key check” (page 22).

2. Judgment from the voltage measurement

Judge the right and wrong of the switch by the voltage measure- ment with a test point.

2-1. [u]/[>]/[.] keys

Connection:

	digital voltmeter
CL881 (KEY_AD0)	+
CL885 (GND)	–

When the voltage value is below, [u]/[>]/[.] keys are

normal.
• [u] key is pressed		: 0 to 0.25 V
•	[>] key is pressed	: 0.4 to 0.6 V
•	[.] key is pressed	: 0.76 to 0.95 V

2-2. [VOL +]/[VOL –]/[HOME] keys Connection:

	digital voltmeter
CL882 (KEY_AD1)	+
CL885 (GND)	–

When the voltage value is below, [VOL +]/[VOL –]/[HOME] keys are normal.

•[VOL –] key is pressed : 0 to 0.25 V

•[VOL +] key is pressed : 0.4 to 0.6 V

•[HOME] key is pressed : 0.76 to 0.95 V

2-3. HOLD switch (S881) Connection:

digital voltmeter

S881 (HOLD SW pin 2) +

CL885 (GND) –

When the voltage value is below, HOLD switch (S881) is normal.

•HOLD switch is turned on : 2.85 V

•HOLD switch is turned off : 0 V

NWZ-X1050/X1051/X1060/X1061

Connection location:

– MAIN Board (Side B) –

S881

2 (HOLD SW)

S881 1

CL882

(KEY_AD1)CL885 (GND)

CL881 (KRY_AD0)

7