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SAFETY CHECK-OUT
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.
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
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 B+ voltage to see it is at the values specified.
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.
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TABLE OF CONTENTS
Section Title Page Section Title Page
SERVICE NOTE...................................................................... 4
1. GENERAL
Getting Started .............................................................. 1-1
Basic Operations ........................................................... 1-5
Additional Operations.................................................... 1-8
Editing............................................................................ 1-11
Additional Information ................................................... 1-12
2. DISASSEMBLY
2-1. Upper Case Removal.................................................... 2-1
2-2. RJ-79, NK-11 Board Removal....................................... 2-1
2-3. Rear Panel Removal ..................................................... 2-1
2-4. Front Panel Section Removal ....................................... 2-1
2-5. FR-137, DM-77, SW-307, IO-64 Board
Removal (ED9).............................................................. 2-2
2-6. Control Switch Block Removal (ED9) ........................... 2-2
2-7. FR-137, DM-77, IO-64 Board Removal (ED8) ............. 2-2
2-8. Mechanism Deck Removal ........................................... 2-2
2-9. Power Block Removal ................................................... 2-3
2-10. PS-414, MA-325 board Removal .................................. 2-3
2-11. Internal Views................................................................ 2-4
2-12. Circuit Boards Location ................................................. 2-5
3. BLOCK DIAGRAMS
3-1. Overall Block Diagram .................................................. 3-1
3-2. Video1 Block Diagram ................................................... 3-4
3-3. Video2 Block Diagram ................................................... 3-5
3-4. Servo/System control Block Diagram ........................... 3-7
3-5. Audio Block Diagram..................................................... 3-9
3-6. Tuner Block Diagram ..................................................... 3-11
3-7. Mode Control Block Diagram ........................................ 3-13
3-8. Power Block Diagram.................................................... 3-15
4. PRINTED WIRING BOARDS AND
SCHEMATIC DIAGRAMS
4-1. Frame Schematic Diagram ........................................... 4-3
4-2. Printed Wiring Boards and Schematic Diagrams ......... 4-5
MA-325 (Head Amp) Schematic Diagram .................... 4-5
MA-325 Printed Wiring Board ....................................... 4-9
MA-325 (Video, Audio) Schematic Diagram................. 4-11
MA-325 (System Control) Schematic Diagram ............ 4-15
MA-325 (Servo Control) Schematic Diagram ............... 4-17
MA-325 (Bias, CTL) Schematic Diagram ..................... 4-19
MA-325 (Hi-Fi Audio) Schematic Diagram .................... 4-21
MA-325 (OSD) Schematic Diagram.............................. 4-23
MA-325 (IO) , RJ-79 Schematic Diagrams and
RJ-79 Printed Wiring Board .......................................... 4-25
MA-325 (Tuner) Schematic Diagram ............................ 4-27
NK-11 Printed Wiring Board and
Schematic Diagram ....................................................... 4-29
DM-77, IO-64 Printed Wiring Boards and
Schematic Diagrams ..................................................... 4-31
FR-137, SW-307 Printed Wiring Boards....................... 4-33
FR-137, SW-307 Schematic Diagram .......................... 4-35
PS-414 Printed Wiring Board........................................ 4-37
PS-414 Schematic Diagram.......................................... 4-39
SR-718 Printed Wiring Board ....................................... 4-41
SR-718 Schematic Diagram ......................................... 4-43
5. INTERFACE, IC PIN FUNCTION DESCRIPTION
5-1. System Control-Video Block Interface
(MA-325 board IC161) .................................................. 5-1
5-2. System Control-Servo Peripheral Circuit Interface
(MA-325 board IC161) .................................................. 5-1
5-3. System Control-Mechanism Block Interface
(MA-325 board IC161) .................................................. 5-2
5-4. System Control-System Control Peripheral Circuit
Interface (MA-325 board IC161) ................................... 5-3
5-5. System Control-Hi-Fi Audio Block Interface
(MA-325 board IC161) .................................................. 5-3
5-6. Servo/System Control Microprocessor Pin Function
(MA-325 board IC161) .................................................. 5-4
5-7. Timer/Tuner Control Microprocessor Pin Function
(FR-137 board IC301) ................................................... 5-5
5-8. KOREAN Processor Pin Function
(NK-11 board IC1) ......................................................... 5-6
6. ERROR CODE.......................................................... 6-1
7. ADJUSTMENTS
7-1. Mechanical Adjustments ............................................... 7-1
7-2. Adjustments................................................................... 7-1
2-1. EEP ROM Initial Data Input .......................................... 7-1
7-3. Electrical Adjustments................................................... 7-1
3-1. Pre-Adjustment Preparations........................................ 7-1
3-1-1. Instruments to be Used............................................ 7-1
3-1-2. Connection ............................................................... 7-1
3-1-3. Set-up of Adjustment ............................................... 7-2
3-1-4. Alignment T apes....................................................... 7-2
3-1-5. Specified I/O Level and Impedance
Input/Output T erminal............................................... 7-2
3-1-6. Adjusting Sequence ................................................. 7-2
3-2. Power Supply Adjustment ............................................. 7-2
3-2-1. Power Supply Check................................................ 7-2
3-2-2. +6 V Adjustment ....................................................... 7-2
3-3. Servo System Adjustment............................................. 7-3
3-3-1. RF Switching Position Adjustment........................... 7-3
3-4. Audio System Adjustments ........................................... 7-3
3-4-1. Hi-Fi Audio System Adjustment ............................... 7-3
1. AF Switching Position Adjustment........................... 7-3
2. Frequency Response Check.................................... 7-4
3. Overall Level Characteristic and
Distortion Factor Check ........................................... 7-4
4. Overall S/N Check.................................................... 7-4
3-4-2. Normal Audio System Adjustment ........................... 7-5
1. ACE Head Adjustment ............................................. 7-5
2. E-E Output Level Check........................................... 7-5
3. Frequency Responce Check.................................... 7-5
4. Overall Level Characteristic and Distortion
Factor Check ............................................................ 7-5
5. Overall S/N Check.................................................... 7-5
3-5. Video System Adjustment ............................................. 7-5
3-5-1. VCO Oscillation Frequency Adjustment .................. 7-5
3-6. Parts Arrangement Diagram for Adjustments............... 7-6
8. REPAIR PARTS LIST
8-1. Exploded Views ............................................................. 8-1
8-1-1. Front Panel and Cabinet Assemblies (ED8)............ 8-1
8-1-2. Front Panel and Cabinet Assemblies (ED9)............ 8-2
8-1-3. Chassis Assembly .................................................... 8-3
8-1-4. Mechanism Chassis Assembly (1)........................... 8-4
8-1-5. Mechanism Chassis Assembly (2)........................... 8-5
8-1-6. Mechanism Chassis Assembly (3)........................... 8-6
8-2. Electrical Parts List........................................................ 8-7