Page 1
Ñ 2 Ñ
1. GENERAL ááááááááááááááááááááááááááááááááááááááááááááááááááá\
ááááááááááááááááááá 7
2. DISASSEMBLY
2-1. Front Panel ááááááááááááááááááááááááááááááááááááááááááááááááááá\
áááááááááááááááááááá 11
2-2. Disc Table Assy ááááááááááááááááááááááááááááááááááááááááááááááááááá\
ááááááááááááá 11
2-3. Back Panel and Disc Table ááááááááááááááááááááááááááááááááááááááááááááááá 12
2-4. Optical Pick-up Block Assembly ááááááááááááááááááááááááááááááááááááá 12
2-5. Bracket (Gear) Assembly ááááááááááááááááááááááááááááááááááááááááááááááááá 13
3. TEST MODE ááááááááááááááááááááááááááááááááááááááááááááááááááá\
ááááááááááááá 14
4. ELECTRICAL BLOCK CHECKING áááááááááááááááááááá 17
5. DIAGRAMS
5-1. Circuit Boards Location ááááááááááááááááááááááááááááááááááááááááááááááááááá\
19
5-2. Block Diagram ááááááááááááááááááááááááááááááááááááááááááááááááááá\
áááááááááááááá 21
5-3. Schematic Diagram Ñ BD Section Ñ ááááááááááááááááááááááááááááá 23
5-4. Printed Wiring Board Ñ BD Section Ñ áááááááááááááááááááááááááá 25
5-5. Printed Wiring Board Ñ Main Section Ñ ááááááááááááááááááááááá 27
5-6. Schematic Diagram Ñ Main Section (1/2)Ñ áááááááááááááááááá 29
5-7. Schematic Diagram Ñ Main Section (2/2)Ñ áááááááááááááááááá 31
5-8. Schematic Diagram Ñ HP/Function Section Ñ áááááááááááááá 33
5-9. Printed Wiring Board Ñ HP/Function Section Ñ ááááááááááá 34
5-10. Schematic Diagram Ñ Display Section Ñ áááááááááááááááááááááá 35
5-11. Printed Wiring Board Ñ Display Section Ñ ááááááááááááááááááá 37
5-12. IC Block Diagrams ááááááááááááááááááááááááááááááááááááááááááááááááááá\
áááááááá 39
5-13. IC Pin Functions ááááááááááááááááááááááááááááááááááááááááááááááááááá\
áááááááááááá 42
6. EXPLODED VIEWS
6-1. Front Panel and Case Section ááááááááááááááááááááááááááááááááááááááááááá 46
6-2. Back Panel and Disc Table Section áááááááááááááááááááááááááááááááááá 47
6-3. Chassis Section ááááááááááááááááááááááááááááááááááááááááááááááááááá\
áááááááááááááá 48
6-4. Base Unit Section (BU-5BD22) ááááááááááááááááááááááááááááááááááááááá 49
7. ELECTRICAL PARTS LIST ááááááááááááááááááááááááááááááááááá 50
TABLE OF CONTENTS
PARTS No. MODEL
MODEL IDENTIFICATION
Ñ BACK PANEL Ñ
4-998-478-0¹
4-998-478-2¹
4-998-478-4¹
4-998-478-5¹ US
E
SP
AEP
yyyyyyyy
PART NO.
Page 2
Ñ 3 Ñ
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINE WITH
MARK ! ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS
LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE
COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS
APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS
PUBLISHED BY SONY.
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, ÒmetallizedÓ knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
described below.
LEAKAGE
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 microamperes).
Leakage 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 manufacturersÕ 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 ÒlimitÓ 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 passive VOM that is suitable. Nearly all battery operated
digital multimeters that have a 2V AC range are suitable. (See
Fig. A)
SAFETY CHECK-OUT
To Exposed Metal
Parts on Set
0.15
µF
1.5 k ½
AC
Voltmeter
(0.75 V)
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic
breakdown because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic breakdown and also use
the procedure in the printed matter which is included in the repair
parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused on
the disc reflective surface by the objective lens in the optical pick-
up block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous
radiation exposure.
Notes on chip component replacement
¥ Never reuse a disconnected chip component.
¥ Notice that the minus side of a tantalum capacitor may be
damaged by heat.
Flexible Circuit Board Repairing
¥ Keep the temperature of soldering iron around 270ûC
during repairing.
¥ Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
¥ Be careful not to apply force on the conductor when soldering
or unsoldering.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
This appliance is classified as
a CLASS 1 LASER product.
The CLASS 1 LASER
PRODUCT MARKING is
located on the rear exterior.
The following
caution label
is located
inside of the
unit.
