Read Sony XM-1505SX / XM-1805GX Service Manual online
8
SECTION 4
ELECTRICAL ADJUSTMENT
Bias Adjustment
Note : The Bias adjustment should be performed only if any of
Q106, Q107, Q206, Q207, Q306, Q307, Q406, Q407, Q506
Q507 and Q509 to Q512 are replaced.
Q507 and Q509 to Q512 are replaced.
Setting :
VR401
BIAS ADJUSTMENT
VR301
BIAS ADJUSTMENT
VR101
BIAS ADJUSTMENT
VR201
BIAS ADJUSTMENT
VR501
BIAS ADJUSTMENT
– AMP BOARD (COMPONENT SIDE) –
Procedure :
1. Rotate the variable resistors VR101, VR201, VR301, VR401
1. Rotate the variable resistors VR101, VR201, VR301, VR401
and VR501 fully in the clockwise direction to minimize the
idling current of the stabilized power supply.
idling current of the stabilized power supply.
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 VR101, VR201, VR301 and VR401 so that the digital
5. Adjust VR101, VR201, VR301 and VR401 so that the digital
voltmeter reading is 5 ± 0.5 mV.
6. Adjust VR501 so that the digital voltmeter reading is
3.5 ± 0.5 mV.
+
_
Stabilized
Power supply
Digital
Voltmeter
B+,REM terminals
set
GND terminal
test points
Adjustment Location :
RV Ref. No.
Test points
VR101
TP101 and TP102
VR201
TP201 and TP202
VR301
TP301 and TP302
VR401
TP401 and TP402
VR501
TP501 and TP502
Test Point Location :
TP401 TP402
TP301
TP302
TP201
TP202
TP101
TP102
TP501
TP502
– AMP BOARD (CONDUCTOR SIDE) –
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