Friday, November 27, 2015

SONY XM-1505SX - 1805GX CAR AMPLIFIER BIAS ADJUSTMENT AND CIRCUIT DIAGRAM

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.

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




 POWER AMP CIRCUIT 
CLICK ON THE IMAGE TO ZOOM IN