XM-7547 - Sony Car Audio Service Manual (repair manual). Page 7

7

7

 Follow the disassembly procedure in the numerical order given.

!™

 CNP806 (2P)

1

 Three screws

     (BTP3x8)

2

 Four screws

     (BTP3x8)

3

 Bottom plate

6

 Side panel (L)

8

 Side panel (R)

7

 Three screws

     (BTP3x8)

!¡

 Auto fuse

    (F901 to 904)

!£

 Screw (BTP3x8)

!∞

 Screw (BTP3x8)

4

 Three screws (BTP3x8)

5

 Two screws (BTP3x8)

9

 Two screws (M4)

0

 Cover

!§

 Filter board

!¢

 Fan motor block

1

 Four screws

     (BTP3x12)

3

 Six screws

     (BVTP3x14)

!™

 Sub heat sink

     (Amplifier)

2

 Three screws

     (P4x40)

!¡

 Three screws

     (P3x6)

8

 Four screws

     (P3x10)

!£

 Four insulating sheets

     (AMP)

9

 Four screws

     (P3x14)

0

 Screw

     (BTP3x8)

4

 Retainers

5

 Two screws

     (BVTP3x10)

6

 Power board

7

 Amplifier board

!¢

 Two screws

     (P2x10)

!∞

 LED board

!§

 LED holder

• Perform adjustments in the  HI-VOLTAGE  mode.

1 Adjustment point

Semi-fixed resistors VR101, VR201, VR301, VR401 of ampli-
fier board.

2 Precautions on adjustments
1. Set the RCA input terminal to open.
2. Apply a voltage of 14.4V between the +12V terminal, REMOTE

terminal, and GND terminal.

3. Rotate the above semi-fixed resistors completely in the counter-

clockwise direction while observing the component side.

4. Check that the voltage at the adjustment point becomes 0 mV in

step 2.

5. Fine adjustments may be required according to the characteris-

tics of the MOS-FET used.

• When adjusting the idling current

Rotating the semi-fixed resistor in the clockwise direction:
In creases the idling current
Rotating the semi-fixed resistor in the counterclockwise direction:

Decreases the idling current

* Take note that rotating excessively in the clockwise direction

will increase the idling current suddenly.

3 Approximate adjustment values

Adjust as follows so that the following voltages become
0.4 to 0.5 mV .

 A channel  :
Voltage between TP101 and TP102: Use VR101 of the ampli-
fier board
 B channel  :
Voltage between TP201 and TP202: Use VR201 of the ampli-
fier board
 C channel  :
Voltage between TP301 and TP302: Use VR301 of the ampli-
fier board
 D channel  :
Voltage between TP401 and TP402: Use VR401 of the ampli-
fier board

TP401(D-CH)

TP201(B-CH)

TP101(A-CH)

TP102(A-CH)

TP202(B-CH)

TP402(D-CH)

IDLING

VR401
(D-CH)

VR301
(C-CH)

IDLING

VR201
(B-CH)

VR101
(A-CH)

TP301(C-CH)

TP302(C-CH)

Digital voltmeter

TP101(A-CH)
TP201(B-CH)
TP301(C-CH)
TP401(D-CH)

TP102(A-CH)
TP202(B-CH)
TP302(C-CH)
TP402(D-CH)