TA-AV571 - Sony Audio Service Manual (repair manual)

— 1 —

US Model

MICROFILM

— 2 —

.......................................................... 3

.......................................................................... 4

3-1. Circuit Boards Location ........................................................ 5
3-2. Waveforms ........................................................................... 6
3-3. Schematic Diagram — Main Section — .............................. 7
3-4. Printed Wiring Board — Main Section — .......................... 11
3-5. Printed Wiring Board — Power Section — ........................ 13
3-6. Printed Wiring Board — Display Section — ...................... 15
3-7. Schematic Diagram — Display Section — ........................ 17
3-8. IC Block Diagrams ............................................................. 19
3-9. IC Pin Function

• IC401 

µ

PD78042FGF-036-3BP (RF System Control) .... 21

4-1. Case and Back Panel Section .............................................. 23
4-2. Front Panel Section ............................................................. 24
4-3. Chassis Section ................................................................... 25

........................................ 26

!

!

To Exposed Metal
Parts on Set

0.15µF

1.5k

Ω

AC
voltmeter
(0.75V)

Earth Ground

After correcting the original service problem, perform the follow-
ing safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
described below.

The AC leakage from any exposed metal part to earth Ground and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microampers). Leak-
age current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA

WT-540A. Follow the manufacturers’ instructions to use these
instruments.

2. A battery-operated AC milliammeter. The Data Precision 245

digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a VOM

or battery-operated AC voltmeter. The “limit” indication is 0.75
V, so analog meters must have an accurate low-voltage scale.
The Simpson 250 and Sanwa SH-63Trd are examples of a pas-
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable. (See Fig. A)

— 3 —

[Fluorescent Indicator Tube, LED All Lit, and Key Check Mode]
1. When the plug is inserted into the outlet while pressing the

 3 CLASSIC  button, the fluorescent indicator tube and LED
will light up completely.

2. The mode changes as follows each time the  3 CLASSIS  button

and  DBFB ON/OFF  button are pressed together after 1.

Sequence of Service Modes

Fluorescent Indicator
Tube and LED Check Mode

*1

 AMP check mode

*2

 KEY check mode

*3

• Press the  3 CLASSIC  button and  DBFB ON/OFF

button at the same time.

• Press the  3 CLASSIC  button and  DBFB ON/OFF

button at the same time.

• Press the  3 CLASSIC  button and  DBFB ON/OFF

button at the same time.

*1 For checking if the fluorescent indicator tube and LED are lit

completely

*2 When the AMP check mode is set, “AMP” is displayed on the

fluorescent indicator tube. As this mode is not used for servic-
ing, perform step 2 to enter the KEY check mode.

*3 When the KEY check mode is set, “KEY 0” is displayed on the

fluorescent indicator tube. Each press of the button is counted.
(This excludes the  POWER  button)
When all buttons are pressed, the AMP check mode is set.
Buttons pressed once will not be counted when pressed again.

3. To exit the test mode, press the  POWER  button.

— 4 —

1 POWER button
2 CENTER MODE button
3 DOLBY PRO LOGIC indicator
4 SURROUND MODE buttons

(DOLBY, HALL, SIMULATED)

5 SURROUND indicators

(DOLBY, HALL, SIMULATED)

6 – button
7 Display window
8 + button
9 SOUND CONTROL indicators

(BASS, TREBLE, CENTER, REAR)

!º CONTROL MODE buttons

(BASS, TREBLE, CENTER, REAR)

!¡ DBFB indicator

!™ DBFB ON/OFF button
!£ MASTER VOLUME Knob
!¢ PHONO button
!∞ 5 GAME button
!§ TUNER button
!¶ 4 MOVIE button
!• CD button
!ª 3 CLASSIC button
@º TAPE button
@¡ 2 POPS button
@™ VIDEO 2 button
@£ 1 ROCK button
@¢ VIDEO 1 button
@∞ PHONES jack

1

2

3 4 5

6

7

8

0

9

!¡

!™

!£

!¢

!∞

!§

!¶

!•

!ª

@º

@¡

@™

@£

@¢

@∞

This section is extracted from
instruction manual.