Electrical Adjustment - Sony XM-460GTX Service Manual

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Service manual (24 pages)

Operating instructions manual (7 pages)

Operating instructions (4 pages)

Table Of Contents

Table of Contents

Bias Adjustment

Note : The Bias adjustment should be performed only if any of

Q109 and Q110 for RV104, Q209 and Q210 for RV204,

Q309 and Q310 for RV304, and Q409 and Q410 for RV404

are replaced.

Setting :

stabilized

power supply

B+, REM terminals

GND terminal

Procedure:

1. Rotate variable resistors RV104 (FRONT L-CH), RV204

(FRONT R-CH), RV304 (REAR L-CH) and RV404 (REAR

R-CH) full clockwise as seen from the pattern side to minimize

the bias current.

2. The input signal is with no signal.

3. Connect the stabilized power supply between B+ and REM

terminals and gradually increase the voltage to 14.4 V while

checking for any abnormal current.

4. Adjust RV104 (FRONT L-CH), RV204 (FRONT R-CH), RV304

(REAR L-CH) and RV404 (REAR R-CH) so that the digital

voltmeter connected between the respective test points reads

6±1 mV.

RV Ref. No.

Test points

RV104

TP11 and TP12

RV204

TP21 and TP22

RV304

TP31 and TP32

RV404

TP41 and TP42

5. After this adjustment, verify that the current value of the

stabilized power supply is 1.4 to 1.8 A.

Adjustment Location :

– MAIN BOARD (CONDUCTOR SIDE) –

BIAS ADJUSTMENT

(REAR L-CH)

TP42

RV404

BIAS ADJUSTMENT

(REAR R-CH)

BIAS ADJUSTMENT

(FRONT R-CH)

SECTION 3