Sony hcd gtr 33 gtr 55 gtr 77

Page 2

HCD-GTR33IGTR55IGTR77

NOTES ON CHIP COMPONENT REPLACEMENT

- Never reuse a disconnected chip component.

- Notice that the minus side ofa 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 CHECK-OUT

Alter 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 pan to earth ground and from all

exposed metal parts to any exposed metal pan 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 thisjob.

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
VAC range are suitable. (See Fig. A)

To Exposed Metal
Parts on Set
AC
0.15 uF g 1.5 k0 / voltmeter
(o. 75 V)

_7_ Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.

CAUTION

Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radia-
tion exposure.

cmss USER manner This appliance is classiticd as a CLASS 1
LUOKAN r LASERLAITE LASER product. This marking is located on
the rear exterior.

mass 1 LASERAPFARAT

SAFETY-RELATED COMPONENT WARNING!

COMPONENTS IDENTIFIED BY MARK A OR DOTTED LINE
WITH MARK A 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.

2

2-6.
2-7.
2-8.

2-10.

6-21.
6-22.
6-23.
6-24.

7-1.
7-2.
7-3.

7-4.
7-5.
7-6.
7-7.
7-8.
7-9.

. Optical Pick-up Block (KI-IM-313CAB) .....
. Belt (DLM3A) ................................................................

. Schematic Diagram - MAIN Board (1/3)
. Schematic Diagram » MAIN Board (2/3)
. Schematic Diagram - MAIN Board (3/3) -..
. Printed Wiring Board - HUB Board -
. Schematic Diagram - HUB Board -
. Printed Wiring Board - POWER Board -
. Schematic Diagram » POWER Board -
. Printed Wiring Board - DISPLAY Board

TABLE OF CONTENTS
SERVICING NOTES ................................................ 3

DISASSEMBLY
Disassemhly Flow
Case (Side-L/R)
Top Cas .
Tape Mechanr Dec
Front Panel Block, HUB Board,
DMB19 Board ......
DC Fan (M101), Back Panel
MAIN Board.
POWER Board.
Chassis Section
CD Mechanism Block (CDMSBBDVBUIOI)

ammu-

ooooxmqq

TEST MODE ..

MECHANICAL ADJUSTMENTS ........................

L»

ELECTRICAL CHECK .......................................... l4

DIAGRAMS
Block Diagram - RF SERVO, USB Section - ................. 15
Block Diagram - MAIN Section
Block Diagram - AMP Section -.
Block Diagram

- PANEL, POWER SUPPLY Section -.
Printed Wiring Board - DMB19 Board
Schematic Diagram - DMB19 Board (1/3) -
Schematic Diagram - DMBI) Board (2/3) -
Schematic Diagram - DMB19 Board (3/3) -
Printed Wiring Board - MAIN Board -.

17

. Schematic Diagram » DISPLAY Board - ........................ 33
. Printed Wiring Board
- MIC, USE AND VOLUME Board - ........................ 34

. Schematic Diagram

- MIC, USE AND VOLUME Board -
Printed Wiring Board - TC Board
Schematic Diagram - TC Board »
Printed Wiring Board - TRANS Board
Schematic Diagram - TRANS Board - .

35

38

EXPLODED VIEWS
Case Section .................................................................... 49

Top Panel Section .................... ................... 50
Loading Panel Section, HUB Board Section, DMB19
Board Section ................. 51
DISPLAY Board Section. 52
Front Panel Section 53
Back Panel Section 54
MAIN Board Section 55
Chassis Section .............................................................. 56
CD Mechanism Section

(CDMSSB-DVBUIOI) ................................................... 57
ELECTRICAL PARTS LIST ............................... 58