Read Sony XM-1004GX / XM-754SX Service Manual online
8
Bias Adjustment
Note : The Bias adjustment should be performed only if any of
Q109, Q110, Q113, Q209, Q210, Q213, Q309, Q310, Q311
Q409, Q411 and Q413 are replaced.
Q409, Q411 and Q413 are replaced.
Setting :
SECTION 3
ELECTRICAL ADJUSTMENT
RV104
BIAS ADJUSTMENT
RV204
BIAS ADJUSTMENT
RV304
BIAS ADJUSTMENT
RV404
BIAS ADJUSTMENT
– MAIN BOARD (COMPONENT SIDE) –
Procedure :
1. Rotate the variable resistors RV104, RV204, RV304 and RV404
1. Rotate the variable resistors RV104, RV204, RV304 and RV404
fully in the counterclockwise direction to minimize the idling
current of the stabilized power supply.
(The direction of rotation is based on the component side.)
current of the stabilized power supply.
(The direction of rotation is based on the component side.)
2. The input signal is to be no signal.
3. Set the power voltage to +14.4 V, and turn the remote mode ON
3. Set the power voltage to +14.4 V, and turn the remote mode ON
(Connect between the REM terminal and B+ terminal).
4. Connect on digital voltmeter between each test points.
5. Adjust RV104, RV204, RV304 and RV404 so that the digital
5. Adjust RV104, RV204, RV304 and RV404 so that the digital
voltmeter reading is 5 ± 0.5 mV.
+
_
Stabilized
Power supply
Digital
Voltmeter
B+,REM terminals
set
GND terminal
test points
Adjustment Location :
RV Ref. No.
Test points
RV104
TP11 and TP12
RV204
TP21 and TP22
RV304
TP31 and TP32
RV404
TP41 and TP42
Test Point Location :
TP31
TP32
TP33
TP42
TP41
TP43
TP21
TP22
TP23
TP11
TP12
TP13
– MAIN BOARD (CONDUCTOR SIDE) –
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