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WARNING!!
WHEN SERVICING, DO NOT APPROACH THE LASER
EXIT WITH THE EYE TOO CLOSELY. IN CASE IT IS
NECESSARY TO CONFIRM LASER BEAM EMISSION,
BE SURE TO OBSERVE FROM A DISTANCE OF
MORE THAN 25 cm FROM THE SURFACE OF THE
OBJECTIVE LENS ON THE OPTICAL PICK-UP BLOCK.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
ATTENTION AU COMPOSANT AYANT RAPPORT
Ã- LA SÉCURITÉ!
LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE
SUR LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE
DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ
DE FONCTIONNEMENT. NE REMPLACER CES COM-
POSANTS QUE PAR DES PIÈCES SONY DONT LES
NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY. 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 PUB-
LISHED BY SONY.
CAUTION:
The use of optical instrument with this product will increase eye
hazard.
Fig. A. Using an AC voltmeter to check AC leakage.
1.5 k -„¦ 0.15 µF AC
voltmete r (0.75 V) To Exposed Metal
Parts on Set
Earth Ground
LEAKAGE TEST
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 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 indica-
tion is 0.75 V, so analog meters must have an accurate low-
voltage scale. The Simpson 250 and Sanwa SH-63Trd are ex-
amples of a passive VOM that is suitable. Nearly all battery
operated digital multimeters that have a 2 V AC range are suit-
able. (See Fig. A) 1. Check the area of your repair for unsoldered or poorly-sol-
dered connections. Check the entire board surface for solder
splashes and bridges.
2. Check the interboard wiring to ensure that no wires are
pinched or contact high-wattage resistors.
3. Look for unauthorized replacement parts, particularly transis-
tors, that were installed during a previous repair. Point them
out to the customer and recommend their replacement.
4. Look for parts which, though functioning, show obvious signs
of deterioration. Point them out to the customer and recom-
mend their replacement.
5. Check the line cord for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
6. Check the B+ voltage to see it is at the values specified.
7. Check the antenna terminals, metal trim, metallized knobs,
screws, and all other exposed metal parts for AC leakage.
Check leakage as described below.
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
: LEAD FREE MARK Unleaded solder has the following characteristics.
Unleaded solder melts at a temperature about 40°C higher than
ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350°C .
Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!
Strong viscosity
Unleaded solder is more viscous (sticky, less prone to flow) than
ordinary solder so use caution not to let solder bridges occur
such as on IC pins, etc.
Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
Page 2
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SERVICE NOTE ................................................................... 4
1. GENERAL ................................................................... 1
2. DISASSEMBLY
2-1. LID Assembly Removal................................................. 2-1
2-2. Disk Base Assembly Removal ...................................... 2-1
2-3. Base Unit Removal........................................................ 2-1
2-4. BU Holder Removal ....................................................... 2-1
2-5. SW-406 Board Removal................................................ 2-2
2-6. HP-137 & Jack Plate Removal ...................................... 2-2
2-7. Lower Case Removal.................................................... 2-2
2-8. Power Switching Regulator Block Removal................. 2-2
2-9. Shield Plate Removal.................................................... 2-3
2-10. AV-77 Board Removal................................................... 2-3
2-11. IF-106 Board Removal.................................................. 2-3
2-12. MB-108 & SW-407 Boards Removal............................ 2-3
2-13. Circuit Boards Location................................................. 2-4
3. BLOCK DIAGRAMS
3-1. Overall Block Diagram................................................... 3-1
3-2. System Control Block Diagram..................................... 3-3
3-3. RF/Servo Block Diagram............................................... 3-5
3-4. Signal Processor Block Diagram.................................. 3-7
3-5. Video/Audio Block Diagram.......................................... 3-9
3-6. Interface Control Block Diagram...................................3-11
3-7. Power 1 Block Diagram.................................................3-13
3-8. Power 2 Block Diagram.................................................3-15
4. PRINTED WIRING BOARDS AND SCHEMATIC
DIAGRAMS
4-1. Printed Wiring Boards and Schematic Diagrams........ 4-1
4-2. Frame Schematic Diagram............................................ 4-3
Waveforms..................................................................... 4-5
- MB-108 Printed Wiring Board.................................. 4-7
MB-108 (System Control) Schematic Diagram....... 4-9
MB-108 (Motor Drive) Schematic Diagram.............4-11
MB-108 (Servo) Schematic Diagram.......................4-13
MB-108 (AV Decoder) Schematic Diagram............4-15
MB-108 (Audio DAC, PLL) Schematic Diagram......4-17
MB-108 Board Differential Part List.........................4-17
AV-77 Printed Wiring Board.....................................4-19
AV-77 (Audio/Video Out) Schematic Diagram........4-21
AV-77 Board Differential Part List............................4-23
IF-106 Printed Wiring Board....................................4-25
IF-106 (Interface Control) Schematic Diagram.......4-27
SW-406, SW-407 Printed Wiring Boards................4-29
SW-406 (Function Switch), SW-407 (Door Switch)
Schematic Diagram.............................................4-31
HP-137 Printed Wiring Board..................................4-33
HP-137 (Headphone) Schematic Diagram.............4-35
DPSN-20CP Printed Wiring Board..........................4-37
DPSN-20CP (Switching Regulator)
Schematic Diagram.............................................4-39
DPSN-20CP-2 Printed Wiring Board.......................4-41
DPSN-20CP-2 (Switching Regulator)
Schematic Diagram.............................................4-43
5. IC PIN FUNCTION DESCRIPTION
5-1. System Control Pin Function
(MB-108 BOARD IC104: MB9130RPFV-G-BND-E1) ... 5-1
6. TEST MODE
6-1. General Description...................................................... 6-1
6-2. Starting Test Mode......................................................... 6-1
6-3. Syscon Diagnosis.......................................................... 6-1
6-4. Drive Auto Adjustment................................................... 6-5
6-5. Drive Manual Operation................................................ 6-7
6-6. Emergency History........................................................6-10
6-7. Version Information .......................................................6-11
6-8. Video Level Adjustment................................................6-11
6-9. Troubleshooting.............................................................6-11
7. ELECTRICAL ADJUSTMENT
7-1. Power Supply Check..................................................... 7-1
7-2. Adjustment of Video System ......................................... 7-2
1. Video Level Adjustment................................................ 7-2
2. Checking S Video Output S-Y....................................... 7-2
3. Checking S Video Output S-C ...................................... 7-2
7-3. Adjustment Related Parts Arrangement....................... 7-3
8. REPAIR PARTS LIST
8-1. Exploded Views............................................................. 8-1
8-1-1. Disk Base Section.................................................... 8-1
8-1-2. Lower Case Section................................................. 8-2
8-2. Electrical Parts List........................................................ 8-3
