Sony WRT-822B, Service Manual

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3-3
WRT-822B
CN301 (RF input)
S401 (–)
S400 (+)
TP501
(GND)
TP500 (+3.0V) S500 (POWER)
TP5V
TP3V
ON
OFF
S402 (SET)
MB-940 Board
(A side)
MB-940 Board
(B side)
CN102
RV101
(
∆
F max)
RV102
(Limitter: Only CE)
CT400 (Freq)
RV300
(RF Power)
RV201
(Tone
∆
F)
RV202 (
∆
F)
CN501
MIC input connector (SMC9-4P)
Adjustment Location
3-2-1. Power Supply Voltage Check
Equipment and Tools Required
DC power supply
DC output voltage:
+
3.0
±
0.1 V dc
DC ammeter
DC volt meter (or Digital multimeter)
Adjuster (Sony Part No. 7-721-052-81)
Switch and Control Setting
The following setting is to be perform with the SET switch
(S402), “
+
” switch (S400) and “
_
” switch (S401).
Transmitting Channel setting:“Don't Care”
Attenuation setting:
“Don't Care”
Accumulated time setting: “Don't Care”
Procedure
(1) Set the POWER switch (S500) on the MB-940 board to
ON.
(2) Check the DC Voltage of the TP5V terminal to the spec-
ified voltage as below:
Specification: DC Voltage at TP5V terminal
=
+
5.0
±
0.1 V dc (For Vcc1)
(3) Check the DC voltage of the TP3V terminal to the spec-
ified voltage as below:
Specification: DC voltage at TP3V terminal
=
+
3.3
±
0.1 V dc (For Vcc2)
TP501
(GND)
TP5V
TP3V
ON
MB-940 Board
(A side)
DC voltmeter