HCD-GTR33/GTR55/GTR77
2
TABLE OF CONTENTS
NOTES ON CHIP COMPONENT REPLACEMENT
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
FLEXIBLE CIRCUIT BOARD REPAIRING
• Keep the temperature of soldering iron around 270 °C 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 unsol-
dering.
SAFETY-RELATED COMPONENT WARNING!
COMPONENTS IDENTIFIED BY MARK
0
OR DOTTED LINE
WITH MARK
0
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.
CAUTION
Use of controls or adjustments or performance of procedures
other than those speci
fi
ed herein may result in hazardous radia-
tion exposure.
SAFETY CHECK-OUT
After correcting the original service problem, perform the following safe-
ty check 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.
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 instru-
ments.
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 passive VOM that is
suitable. Nearly all battery operated digital multimeters that have a 2
V AC range are suitable. (See Fig. A)
1.5 k
Ω
0.15
μ
F
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
1. SERVICING
NOTES
................................................ 3
2. DISASSEMBLY
2-1. Disassembly
Flow
........................................................... 5
2-2. Case
(Side-L/R)
.............................................................. 5
2-3. Top
Case.......................................................................... 6
2-4. Tape Mechanism Deck .................................................... 6
2-5. Front Panel Block, HUB Board,
DMB19
Board
.................................................................
7
2-6. DC Fan (M101), Back Panel ........................................... 7
2-7. MAIN
Board
................................................................... 8
2-8. POWER
Board
................................................................ 8
2-9. Chassis
Section
............................................................... 9
2-10. CD Mechanism Block (CDM88B-DVBU101) ............... 9
2-11. Optical Pick-up Block (KHM-313CAB) ........................ 10
2-12. Belt (DLM3A) ................................................................ 10
3.
TEST MODE
............................................................. 11
4. MECHANICAL
ADJUSTMENTS
........................ 13
5.
ELECTRICAL CHECK
.......................................... 14
6. DIAGRAMS
6-1. Block Diagram - RF SERVO, USB Section - ................. 15
6-2. Block Diagram - MAIN Section - ................................... 16
6-3. Block Diagram - AMP Section - ..................................... 17
6-4. Block
Diagram
- PANEL, POWER SUPPLY Section - ........................... 18
6-5. Printed Wiring Board - DMB19 Board - ........................ 20
6-6. Schematic Diagram - DMB19 Board (1/3) - .................. 21
6-7. Schematic Diagram - DMB19 Board (2/3) - .................. 22
6-8. Schematic Diagram - DMB19 Board (3/3) - .................. 23
6-9. Printed Wiring Board - MAIN Board - ........................... 24
6-10. Schematic Diagram - MAIN Board (1/3) - ..................... 25
6-11. Schematic Diagram - MAIN Board (2/3) - ..................... 26
6-12. Schematic Diagram - MAIN Board (3/3) - ..................... 27
6-13. Printed Wiring Board - HUB Board - ............................. 28
6-14. Schematic Diagram - HUB Board - ................................ 29
6-15. Printed Wiring Board - POWER Board - ........................ 30
6-16. Schematic Diagram - POWER Board - .......................... 31
6-17. Printed Wiring Board - DISPLAY Board - ..................... 32
6-18. Schematic Diagram - DISPLAY Board - ........................ 33
6-19. Printed Wiring Board
- MIC, USB AND VOLUME Board - ........................ 34
6-20. Schematic Diagram
- MIC, USB AND VOLUME Board - ........................ 35
6-21. Printed Wiring Board - TC Board - ................................. 36
6-22. Schematic Diagram - TC Board - ................................... 36
6-23. Printed Wiring Board - TRANS Board - ......................... 37
6-24. Schematic Diagram - TRANS Board - ........................... 38
7.
EXPLODED VIEWS
7-1. Case
Section
.................................................................... 49
7-2. Top Panel Section ........................................................... 50
7-3. Loading Panel Section, HUB Board Section, DMB19
Board Section .................................................................. 51
7-4. DISPLAY Board Section ............................................... 52
7-5. Front Panel Section ........................................................ 53
7-6. Back Panel Section ........................................................ 54
7-7. MAIN Board Section ..................................................... 55
7-8. Chassis Section .............................................................. 56
7-9. CD Mechanism Section
(CDM88B-DVBU101) ................................................... 57
8.
ELECTRICAL PARTS LIST
............................... 58
This appliance is classified as a CLASS 1
LASER product. This marking is located on
the rear exterior.
