Sony SLV-778HF, SLV-788HF, RMT-V231B, RMT-V232B Service Manual

SLV-777HF/778HF/788HF

RMT-V231B/V232B

US Model

Canadian Model

SLV-777HF/778HF/788HF

PX Model

SLV-777HF

SERVICE MANUAL

VIDEO CASSETTE RECORDER

MICROFILM

S MECHANISM

• Refer to the SERVICE MANUAL of VHS MECHANICAL ADJUSTMENT

for MECHANICAL ADJUSTMENTS.

(9-921-647-11)

G j

SPECIFICATIONS

Photo : SLV-788HF

— 2 —

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK ! OR DO TTED 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.

ATTENTION AU COMPOSANT AYANT RAPPORT

À LA SÉCURITÉ! LES COMPOSANTS IDENTIFÉS P AR UNE MARQUE ! SUR LES DIAGRAMMES SCHÉMA TIQUES ET LA LISTE DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.

DIFFERENT SPECIFICATIONS

MODEL

SPECIFICATIONS

BODY COLOR REMOTE COMMANDER

SLV-788HF

BLACK

RMT-V232B

SLV-778HF

BLACK

RMT-V231B

SLV-777HF

US, Canadian PX

TITAN BLACK

RMT-V231B

— 3 —

SAFETY CHECK-OUT

After correcting the original service problem, perform the following safety checks before releasing the set to the customer.

1. Check the area of your repair for unsoldered or poorly-soldered 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 transistors, 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 recommend 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.

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 0.5mA (500 microampers). Leakage current can be measured by any one of three methods.

1. A commercial leakage tester, such as the Simpson 229 or RCA TW-540A. F ollow the manufacturers' instructions to use these instruments.

2. A battery-operated A C 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 v oltmeter . The "limit" indication is 0.75V, 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 A C range are suitable. (See Fig. A)

T o Exposed Metal

Parts on Set

0.15

1.5 k

Ω

AC Voltmeter (0.75 V)

Earth Ground

Fig. A. Using an A C v oltmeter to check A C leakage.

— 4 —

SERVICE NOTE

1. ERROR CODE INDICATION··········································· 6

2. HOW TO REPLACE A ROTARY UPPER DRUM (777HF, 778HF MODEL) ·················································· 7

2-1. HOW TO REMOVE A ROTARY UPPER DRUM ············ 7 2-2. HOW TO ATTACH A NEW ROTARY

UPPER DRUM··································································· 7

1. GENERAL

Getting Started

Unpacking··············································································1-1 Setting up the remote commander ·········································1-1 Hookups ·················································································1-1 Selecting a language ······························································1-7 Setting the clock ···································································· 1-7 Setting up cable box control ··················································1-9 Presetting channels ······························································1-10 Setting up VCR Plus+··························································1-11

Basic Operations

Playing a tape·······································································1-12 Recording TV programs ······················································1-13 Recording TV programs using VCR Plus+ ·························1-14 Setting the timer manually···················································1-14

Additional Operations

Playing/searching at various speeds ····································1-15 Searching for a selected point on the tape ···························1-16 Skip-searching automatically···············································1-16 Recording TV programs using the quick timer ···················1-16 Checking/changing/cancelling timer settings ······················1-17 Recording stereo and bilingual programs ····························1-17 Adjusting the picture ···························································1-18 Changing menu options ·······················································1-18 Editing with another VCR ···················································1-18

Additional Information

General setup information ···················································1-19 Index to parts and controls···················································1-19

2. DISASSEMBLY

2-1. UPPER CASE,

FRONT PANEL BLOCK ASSEMBLY ·························· 2-1

2-2. FR-138 BOARD, DM-80 BOARD ·································2-1 2-3. REAR PANEL ·································································2-1 2-4. POWER BLOCK, MA-327 BOARD (WITH S

MECHANISM DECK) ···················································2-2

2-5. S MECHANISM DECK ················································· 2-2 2-6. INTERNAL VIEWS························································2-3 2-7. CIRCUIT BOARDS LOCATION···································2-4

3. BLOCK DIAGRAMS

3-1. OVERALL BLOCK DIAGRAM····································3-1 3-2. VIDEO BLOCK DIAGRAM ··········································3-3 3-3. SERVO/SYSTEM CONTROL BLOCK DIAGRAM ····· 3-5 3-4. AUDIO BLOCK DIAGRAM ··········································3-7 3-5. MODE CONTROL BLOCK DIAGRAM ·······················3-9 3-6. TUNER BLOCK DIAGRAM ·······································3-11 3-7. POWER SUPPLY BLOCK DIAGRAM ·······················3-13

4. PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS

4-1. FRAME SCHEMATIC DIAGRAM································4-1 4-2. PRINTED WIRING BOARDS AND

SCHEMATIC DIAGRAMS ············································ 4-3

• MA-327 (REC/PB AMP, VIDEO, SERVO/SYSTEM CONTROL, AUDIO, TUNER)

PRINTED WIRING BOARD ·························4-3

• MA-327 (REC/PB AMP) SCHEMATIC DIAGRAM ······························4-5

• MA-327 (VIDEO, NORMAL AUDIO) SCHEMATIC DIAGRAM ······························4-8

• MA-327 (SERVO/SYSTEM CONTROL) SCHEMATIC DIAGRAM ····························4-11

• MA-327 (ON SCREEN DISPLAY) SCHEMATIC DIAGRAM···························· 4-15

• MA-327 (AFM AUDIO) SCHEMATIC DIAGRAM···························· 4-17

• MA-327 (TUNER) SCHEMATIC DIAGRAM···························· 4-19

• MA-327 (POWER SUPPLY, AV BUS) SCHEMATIC DIAGRAM···························· 4-21

• FR-138 (MODE CONTROL) PRINTED WIRING BOARD ·······················4-23

• FR-138 (MODE CONTROL) SCHEMATIC DIAGRAM ····························4-25

• DM-80 (OPERATION SWITCHES) PRINTED WIRING BOARD AND SCHEMATIC DIAGRAM ····························4-27

• JK-162 (LINE-2 IN) PRINTED WIRING BOARD AND SCHEMATIC DIAGRAM ····························4-28

• POWER BLOCK SR801 (SWITCHING REGULATOR) PRINTED WIRING BOARD AND SCHEMATIC DIAGRAM ····························4-29

• POWER BLOCK SR709 (SWITCHING REGULATOR) PRINTED WIRING BOARD AND SCHEMATIC DIAGRAM ····························4-31

5. INTERFACE, IC PIN FUNCTION DESCRIPTION

5-1. SYSTEM CONTROL —

MECHANISM BLOCK INTERFACE (MA-327 BOARD IC160)···············································5-1

5-2. SYSTEM CONTROL —

SERVO PERIPHERAL CIRCUIT INTERFACE (MA-327 BOARD IC160)···············································5-1

5-3. SYSTEM CONTROL — SYSTEM CONTROL

PERIPHERAL CIRCUIT INTERF ACE (MA-327 BOARD IC160)···············································5-2

5-4. SYSTEM CONTROL AND RF MODULATOR—

INPUT SELECTION BLOCK INTERFACE (MA-327 BOARD IC160)···············································5-2

5-5. SYSTEM CONTROL —

VIDEO/RP BLOCK INTERFACE (MA-327 BOARD IC160)···············································5-2

5-6. SYSTEM CONTROL —

AUDIO BLOCK INTERFACE (MA-327 BOARD IC160)···············································5-2

5-7. SERVO/SYSTEM CONTROL MICROPROCESSOR

(MA-327 BOARD IC160)···············································5-3

6. ADJUSTMENTS

6-1 MECHANICAL ADJUSTMENTS ·································6-1 6-2. ELECTRICAL ADJUSTMENTS ···································6-1 2-1. PREPARATION BEFORE ADJUSTMENT ···················6-1 2-1-1.Equipment Required ························································6-1 2-1-2.Equipment Connection ···················································· 6-1 2-1-3.Input Signal Check ··························································6-1 2-1-4.Alignment Tape ·······························································6-1 2-1-5.Input/Output Levels and Impedance ······························· 6-2 2-1-6.Adjustment Sequence ······················································ 6-2 2-2. POWER SUPPLY CHECK ············································· 6-2 2-2-1.Output Voltage Check (MA-327 Board) ·························6-2 2-3. SERVO SYSTEM CHECK ·············································6-3 2-3-1.RF Switching Position/

AF Switching Position Adjustments (MA-327 Board) ···6-3

TABLE OF CONTENTS

— 5 —

2-4. VIDEO SYSTEM CHECKS ···········································6-4 2-4-1.X’tal OSC Check (MA-327 Board)·································6-4 2-4-2.SYNC AGC Check (MA-327 Board)······························6-4 2-4-3.Recording Y Level Check (MA-327 Board) ···················6-4 2-4-4.Recording Chroma Level Check(MA-327 Board) ··········6-5 2-4-5.Playback Level Check (MA-327 Board) ·························6-5 2-5. AUDIO SYSTEM ADJUSTMENT·································6-5 2-5-1.ACE Head Adjustment ····················································6-5 2-5-2.E-E Output Level Check ················································· 6-5 2-5-3.Overall Output Level and Distortion Factor Check·········6-6 2-5-4.Overall Noise Level Check··············································6-6 2-6. TUNER SYSTEM ADJUSTMENT································6-6 2-6-1.Separation Adjustment (MA-327 Board) ························6-6 2-7. ADJUSTING PARTS LOCATION DIAGRAM·············6-8

7. REPAIR PARTS LIST

7-1. EXPLODED VIEWS ······················································7-1 7-1-1.FRONT PANEL ASSEMBLY AND UPPER CASE

SECTION ········································································7-1 7-1-2.CHASSIS SECTION·······················································7-2 7-1-3.MECHANISM DECK-1 ················································· 7-3 7-1-4.MECHANISM DECK-2 ················································· 7-4 7-1-5.MECHANISM DECK-3 ················································· 7-5 7-2. ELECTRICAL P ARTS LIST ··········································7-6

— 6 —

1. ERROR CODE INDICATION

• Error codes are indicated using the lower 5 digits in the fluorescent display tube. “At this time, Colon “:” between character is not indicated.”

ERROR CODE

MODE CODE

0 Power-on eject 10 FWD x1 20 REW play 1 Power-on initial 11 FWD x2 21 Cas. loading 2 Power-off eject 12 CUE 22 Tape loading 3 Power-off stop 13 PB-pause 23 Power-off loading 4 FF 14 RVS-pause 24 Mecha. error (Power on) 5 REW 15 RVS x1 25 Power-on eject initial 6 REC 16 RVS x2 26 Power-off eject initial 7 REC- pause 17 REV 27 APC REC 8 Power-on stop 18 Power-off initial 28 Cas. loading 9 PB 19 Mecha. error (Power off) (No auto PB check)

0 No error 1 Cam encoder error Loading direction 2 Cam encoder error Unloading direction 3 T reel error 4 S reel error 5 Capstan error 6 Drum error 7 Error on initializing 8 Cassette loading error 9 Reserve

Mode code indication when the error has occurred.

Error code

SLV-777HF/778HF/788HF

SERVICE NOTE

— 7 —

2. HOW TO REPLACE A ROTARY UPPER DRUM (777HF, 778HFMODEL)

See below for note.

2-1. HOW TO REMOVE A ROTARY UPPER DRUM

1) Remove screw 1 (+P3 × 8) and remove the ground shaft

assembly 2. (Refer to Fig. 4.)

2) Remove soldering which is marked by arrow and remove the

rotary upper drum board completely.

3) Remove two screws 3 (PSW3 × 8) and remove the rotary

upper drum in the direction of A. (Refer to Fig. 5.) If removal is difficult, remove it while rotating it slowly.

Note: If removal is difficult, check again if soldering is removed

completely.

Fig. 4

2-2. HOW TO ATTACH A NEW ROTARY UPPER

DRUM

1) Pay attention so that finger print or like must not be put when inserting a new upper drum into lower drum.

2) Align mark of the rotary upper drum board with the mark of the rotary transformer board so that the screw hole on the upper drum and that on the lower drum are aligned. (Refer to Fig. 5.)

3) If attaching is difficult, attach a upper drum while rotating it slowly.

Note: Pay attention not to damage the video heads.

Confirm that the upper drum is inserted completely.

4) Tighten the two screws 3 (PSW3 × 8). (Refer to Fig. 5.)

5) Fix the earth shaft 2 by tightening the screw 1 (+P3 × 8) so that protrusion at the tip of the earth shaft contacts the center of the drum shaft.

Note: When attaching the ground shaft assembly 2, never give

force to the plate spring 4.

Fig. 5

Screw (+P3 × 8)

Ground shaft assembly

Drum when viewed from the top

Soldering