CAR AMPLIFIER
SONY XM-1505SX - XM-1805GX
BIAS ADJUSTMENT AND CIRCUIT DIAGRAM
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.
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.
Setting :
Procedure :
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.
2. The input signal is to be no signal.
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 voltmeter reading is 5 ± 0.5 mV. 6. Adjust VR501 so that the digital voltmeter reading is 3.5 ± 0.5 mV.
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
|
Follow the disassembly procedure in the
numerical order given.
PLATE, BOTTOM
AMP BOARD SECTION
CLICK ON THE IMAGE TO ZOOM IN
