Philips VR340/55, VR740/55, VR340/75, VR740/75 Service Manual

Video Cassette Recorder

VR340/55 VR340/75

Service

VR740/55 VR740/75

Service

STOP/EJECT

FWD.PLAYREW.RECORD

STANDBY/ON

CHANNEL

STANDBY/ON

STOP/EJECT

VR340/55/75 VR740/55/75

FWD.PLAYREW.RECORD

CHANNEL

Service Manual

Contents

Chapter

Specifications

Sec. 1:

Adjustment Procedure Schematic Diagrams and CBA's Exploded Views Mechanical and Electrical Parts Lists

Sec. 2:

Standard Maintenance Mechanism Alignment Procedures Disassembly / Assembly of Mechanism Deck Exploded Views

Survey of types:

VR340, VR740: Video Cassette Recorder

Survey of versions:

/55/75 PAL

Safety regulations require that the set be restored to its original condition and that parts which are identical with those specified be used.

Published by BK 2003 Video Service Department Printed in Japan c Copyright reserved Subject to modification GB 3103 785 22210

MAIN SECTION

VIDEO CASSETTE RECORDER

Sec. 1: Main Section

I Specifications I Adjustment Procedures I Schematic Diagrams and CBA’s I Exploded Views I Mechanical and Electrical Parts List

TABLE OF CONTENTS

SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1-1

IMPORTANT SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2-1

STANDARD NOTES FOR SERVICING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3-1

FUNCTION INDICATOR SYMBOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4-1

PREPARATION FOR SERVICING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5-1

OPERATING CONTROLS AND FUNCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6-1

SIGNAL NAME ABBREVIATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7-1

CABINET DISASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8-1

ELECTRICAL ADJUSTMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9-1

Adjustment Points and Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9-2

BLOCK DIAGRAMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10-1

SCHEMATIC DIAGRAMS / CBA’S AND TEST POINTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-1

Main 1/5 Schematic Diagram Parts Location Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-2

Main 1/5 Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-3

Main 2/5 & Sensor & SW1 & SW2 Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-5

Main 2/5 Schematic Diagram Parts Location Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-7

Main 3/5 Schematic Diagram Parts Location Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-8

Main 3/5 Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-9

Main 4/5 Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-11

Main 4/5 Schematic Diagram Parts Location Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-13

Main 5/5 Schematic Diagram Parts Location Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-14

Main 5/5 Schematic Diagram (C,D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-15

AFV Schematic Diagram (C,D). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-17

Main CBA Top View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-19

Main CBA Bottom View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-21

Main CBA Parts Location Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-23

SW1 & SW2 & AFV CBA Top/Bottom View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-25

WAVEFORMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12-1

WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13-1

SYSTEM CONTROL TIMING CHARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14-1

IC PIN FUNCTION DESCRIPTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15-1

LEAD IDENTIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16-1

ELECTRICAL PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17-1

EXPLODED VIEWS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-18-1

SET MECHANICAL PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19-1

VR340CV

SPECIFICATIONS

Comparison Chart of Models and Marks

Model Mark

VR340/55 A

VR340/75 B

VR740/55 C

VR740/75 D

Description Unit Minimum Nominal Maximum Remark

1. Video

1-1. Video Output (PB) Vp-p 0.8 1.0 1.2 SP Mode 1-2. Video Output (R/P) Vp-p 0.8 1.0 1.2

1-3. Video S/N Y (R/P) dB 40 45 1-4. Video Color S/N AM (R/P) dB 37 41 SP Mode

1-5. Video Color S/N PM (R/P) dB 30 36 SP Mode 1-6. Resolution (PB) Line 230 245 SP Mode

2. Servo

2-1. Jitter Low µsec 0.07 0.12 SP Mode 2-2. Wow & Flutter % 0.3 0.5 SP Mode

3. Normal Audio

3-1. Output (PB) dBV -9 -6 -3 SP Mode 3-2. Output (R/P) dBV -9 -6 -1.5 SP Mode 3-3. S/N (R/P) dB 36 41 SP Mode 3-4. Distortion (R/P) % 1.0 4.0 SP Mode 3-5. Freq. resp (R/P) at 200Hz dB -7 -4 SP Mode (-20dB ref. 1kHz) at 6kHz dB -10 -4 SP Mode

4. Tuner

4-1. Video output Vp-p 0.8 1.0 1.2 E-E Mode 4-2. Video S/N dB 39 42 E -E Mode

SP Mode,

W/O Burst

4-3. Audio output dB -10 -6 -2 E-E Mode 4-4. Audio S/N dB 40 46 E-E Mode

5. Hi-Fi Audio [ C, D ]

5-1. Output dBV -12 -8 -4 SP Mode 5-2. Dynamic Range dB 70 85 SP Mode 5-3. Freq. resp (6dB B.W) Hz 20 ~ 20K SP Mode

Note: Nominal specs represent the design specs. All units should be able to approximate these – some will exceed and some may drop s lightly bel ow these spec s. Limit sp ecs rep resent the a bsolute wo rst con dition that still migh t be considered acceptable; In no case should a unit fail to meet limit specs.

1-1-1 HE274SP

IMPORTANT SAFETY PRECAUTIONS

Product Safety Notice

Some electrical and mechanical parts have special safety-related charac teristics which are often not evident from visual inspection, nor can the protection they give necessarily be obtained by replacing them with components rated for higher voltage, wattage, etc. Parts that have spe cial safety characteristics are identified by a ! on schematics and in parts lists. Use of a substitute replacement that does not have the same safety characteristics as the recommended replacement part might create shock, fire, and/or other hazards. The Pro duct’s Safety is und er review con tinuously and new instructions are issued whenever appropriate. Prior to shipment from the factory, our products are carefully inspected to confirm with the recognized product s afety and electrical codes of the countries in which they are to be sold. However, in order to maintain such comp lianc e, it is equ ally impor tant to implement the following precautions when a set is being serviced.

Precautions during Servicing

A. Parts identified by the ! symbol are critical for

safety. Replace only with part number specified. B. In addition to safety, other parts and assemblies

are specified for conformance with regulations

applying to spur ious rad iation. T hese m ust also be

replaced only with specified re pla ce men ts.

Examples: RF converters, RF c ables, noise block-

ing capacitors, and noise blocking filters, etc. C. Use specified internal wiring. Note especially:

1)Wires covered with PVC tubing

2)Double insulated wires

3)High voltage leads

D. Use specified insulating materials for hazardous

live parts. Note especially:

1)Insulation tape

2)PVC tubing

3)Spacers

4)Insulators for transistors

E. When replacing AC primary side components

(transformers, power cord, etc.), wrap ends of

wires securely about the terminals before solder-

ing. F. Observe that the wir es do n ot co ntact h eat pr od uc -

ing parts (heatsinks, oxide metal fil m re sisto rs, fus -

ible resistors, etc.). G. Check that replaced wires do not contact sharp

edges or pointed parts. H. When a power cord h as been repl aced, ch eck that

5 - 6 kg of force in any direction will not loosen it.

I. Also check areas surrounding repaired locations. J. Use care that foreign obj ects (screw s, solder drop-

lets, etc.) do not remain inside the set.

K. Crimp type wire connector

The power tr ansformer uses crimp type connectors which connect the power cord and the primary side of the transformer. When replacing the transformer, follow these steps carefully and precisely to prevent shock hazards. Replacement procedure

1)Remove the old connector by cutting the wires at a point close to the connector.

Important: Do not re-use a connector. (Discard it.)

2)Strip about 15 mm of the insulation from the ends of the wires. If the wires are stranded, twist the strands to avoid frayed conductors.

3)Align the lengths of the wires to be connected. Insert the wires fully into the connector.

4)Use a crimping tool to crimp the metal sleeve at its center. Be sure to crimp fully to th e complete closure of the tool.

L. When connecting or disconnecting the internal con-

nectors, first, disco nnect the AC plug from th e AC outlet.

1-2-1 HE274SFTY

Safety Check after Servicing

Examine the area surrounding the repaired location for damage or deterio ration. Observe that screws , parts, and wires have been returned to their original positions. Afterwards, do the following tests and confirm the specified values to verify compliance with safety standards.

1. Clearance Distance

When replacing primary circuit components, confirm specified cleara nce distanc e (d) and (d’) between sol dered terminals, and between terminals and surrounding metallic parts. (See Fig. 1)

T able 1 : Ratings for selected area

Clearance

AC Line Voltage

110 to 240 V (Auto)

[ VR340/55, VR740/55 ],

240 V [ VR340/75, VR740/75 ]

Note: This table is unofficial and for reference only.

Be sure to confirm the precise values.

Distance

(d) (d’)

≥ 3 mm(d)

≥ 6 mm(d’)

2. Leakage Current Test

Confirm the specified (or lower) leakage current between B (earth ground, power cord plug prongs) and externally exposed accessible parts (RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks, etc.) is lower than or equal to the specified value in the table below.

Measuring Method (Power ON) :

Insert load Z between B (earth ground, power cord plug prongs) and exposed accessible parts. Use an AC voltmeter to measure acr oss the ter minals of l oad Z. See Fig. 2 and the following table.

Chassis or Secondary Conductor

Primary Circuit Terminals

dd'

Fig.

Exposed Accessible Part

AC Voltmeter (High Impedance)

One side of Power Cord Plug Prongs

Fig.

T able 2: Leakage current ratings for selected areas

AC Line Voltage Load Z Leakage Current (i)

2kΩ RES.

110 to 240 V (Auto)

[ VR340/55, VR740/55 ],

240 V [ VR340/75, VR740/75 ]

Note: This table is unofficial and for reference only. Be sure to confirm the precise values.

Connected in

parallel

50kΩ RES.

Connected in

parallel

1-2-2 HE274SFTY

i≤0.7mA AC Peak

i≤2mA DC

i≤0.7mA AC Peak

i≤2mA DC

One side of power cord

plug prongs (B) to:

RF or

Antenna terminals

A/V Input, Output

STANDARD NOTES FOR SERVICING

Circuit Board Indications

a. The output pin of the 3 pin Regulator ICs is indi-

cated as shown.

Top View

Input

b. For other ICs, pin 1 and every fifth pin are indicated

as shown.

in 1

c. The 1st pin of every male connector is indicated as

shown.

in 1

Bottom View

How to Remove / Install Flat Pac k-IC

1. Removal

With Hot-Air Flat Pack-IC Desoldering Machine:.

(1) Prepare the hot-air flat pack-IC desoldering

machine, then apply hot air to the Flat Pack-IC (about 5 to 6 seconds). (Fig. S-1-1)

Fig. S-1-1

(2) Remove the flat pack-IC with tweezers while apply-

ing the hot air.

(3) Bottom of the fla t pack-IC is fixed with glue to the

CBA; when removing entire fl at pack-IC, fir st apply soldering iron to center of the fla t pack-IC and hea t up. Then remove (glue will be melted). (Fig. S-1-6)

(4) Release the fl at pack-IC from the CBA using twee-

zers. (Fig. S-1-6)

Instructions for Connectors

1. When you c onn ect o r di scon nec t the FF C (Fl exib le Foil Connector) cable, be sure to first disconnect the AC cord.

2. FFC (Flexible Foil Connector) cable should be inserted parallel into the connector, not at an angle.

FFC Cable

Connector

CBA

* Be careful to avoid a short circuit.

Caution:

1. Do not supply hot air to the chip parts around the flat pack-IC for over 6 seconds because damage to the chip parts may occur. Put masking tape around the flat pack-IC to protect other parts from damage. (Fig. S-1-2)

2. The flat pack-I C on th e CB A i s a ffixed with g lue , so be careful not to break or damage the foil of each pin or the solder lands under the IC when removing it.

Hot-air Flat Pack-IC Desoldering

CBA

Masking Tape

Tweezers

Machine

Flat Pack-IC

Fig. S-1-2

1-3-1 NOTE_1

With Soldering Iron:

F S

(1)Using desoldering braid, remove the solder from all

pins of the flat pack-IC. Wh en you use solder flux which is applied to all pins of the f lat pack-IC, you can remove it easily. (Fig. S-1-3)

lat Pack-IC

Desoldering Braid

(4) Bottom of the fla t pack-IC is fixed with glue to the

CBA; when removing entire fl at pack-IC, fir st apply soldering iron to center of the fla t pack-IC and hea t up. Then remove (glue will be melted). (Fig. S-1-6)

(5) Release the fl at pack-IC from the CBA using twee-

zers. (Fig. S-1-6)

Note:

When using a sold ering iron, care must be taken to ensure that the flat pack-IC is not being hel d by glue. When the flat pack-IC is removed from the CBA, handle it ge ntl y bec au se it may be damaged if force is applied.

Soldering Iron

Hot Air Blower

Fig. S-1-3

(2) Lift each lead of the flat pack-IC upward one by

one, using a sharp pin or wire to which sold er will not adhere (iron wir e). When heating the pins , us e a fine tip soldering iron or a hot air desoldering machine. (Fig. S-1-4)

Iron Wire

Soldering Iron

To Solid Mounting Point

Fig. S-1-5

Sha Pin

ine Tip oldering Iron

Fig. S-1-4

CBA

Fine Tip Soldering Iro

(3)Bottom of the flat pack-IC is fixed with glue to the

CBA; when removing enti re flat pack-IC, fi rst apply soldering iron to c en ter o f th e f lat pack-I C an d h eat up. Then remove (glue will be melted). (Fig. S-1-6)

(4)Release the flat pack-IC from the CBA us ing twee-

zers. (Fig. S-1-6)

Tweezers

Flat Pack-IC

With Iron Wire:

(1)Using desoldering braid, remove the solder from all

Fig. S-1-6

pins of the flat pack-IC. Wh en you use solder flux which is applied to all pins of the f lat pack-IC, you can remove it easily. (Fig. S-1-3)

(2) Affix the wire to a workbench or solid mounting

point, as shown in Fig. S-1-5.

(3) While heating the pins using a fine tip soldering

iron or hot air blower, pull up the wire as the solde r melts so as to lift the IC leads from the CBA contact pads as shown in Fig. S-1-5

1-3-2 NOTE_1

2. Installation

P i

(1) Using desoldering braid, remove the solder from

the foil of each pin of the flat pack-IC on the CBA so you can install a replac ement flat pack-IC more easily.

(2)The “ I ” mark on the flat pack-IC indi cates pin 1.

(See Fig. S-1-7.) Be sure this mar k matches the 1 on the PCB when position ing for installation. Then presolder the four corne rs of th e fla t pack-IC. (See Fig. S-1-8.)

(3)Solder all pins of the flat pack-IC. Be sure that none

of the pins have solder bridges.

Example :

in 1 of the Flat Pack-IC

s indicated by a " " mark.

Fig. S-1-7

Instructions for Handling Semi-conductors

Electrostatic breakdown of the semi-conductors may occur due to a po tential difference ca used by electr ostatic charge during unpacking or repair work.

1. Ground for Human Body

Be sure to wear a gr oundin g band (1MΩ) that is properly grounded to re move any static electricity th at m ay be charged on the body.

2. Ground for Workbench

Be sure to place a c onductive sheet or copper plate with proper grounding (1MΩ) on the workbench or other surface, where the semi-conductors are to be placed. Because the static electricity charge on clo thing will not escape through the body grounding band , be careful to avoid contacting semi-conductors with your clothing.

< Incorrect >

CBA

Presolder

Flat Pack-IC

Fig. S-1-8

CBA

< Correct >

Grounding Ban

1MΩ

CBA

1MΩ

Conductive Sheet or Copper Plate

1-3-3 NOTE_1

FUNCTION INDICATOR SYMBOLS

Note:

The following symb ol s wil l appear on the indica tor panel to ind icate the current mode or o per at ion of the VCR. On-screen modes will also be momentarily displayed on the tv screen when you press the operation buttons.

Display panel

PWR. REC

" H "= LED Light on, " L "= LED Light off

LED MODE INDICATOR ACTIVE

CASSETTE "IN" CASSETTE "OUT"

CLOCK " 88:88 ON POWER ON " PWR." ON REC " REC " ON REC PAUSE " REC " Blinks at 0.8Hz interval T-REC,OTR

When reel and capstan mechanism is not functioning correctly

When tape loading mechanism is not functioning correctly

When cassette loading mechanism is not functioning correctly

When the drum is not working properly

P-ON Power safety detection

" " " "

" "

" " " 1 "

" " " 2 "

" " " 3 "

" " " 4 "

" " " 5 "

ON OFF

ON (T-REC OFF,T-REC incomplete Blinks at 0.8Hz interval)

Blinks at 0.8Hz interval

S-INH condition All modes Blinks at 0.8Hz interval

1-4-1 HE274FIS

PREPARATION FOR SERVICING

How to Enter the Service Mode

About Optical Sensors

Caution:

An optical sensor system is used for the Tape Start and End Sensors on this equipment. Carefully read and follow the instructions below. Otherwise the unit may operate erratically.

What to do for preparation

Insert a tape into the D eck Mechanis m Assembly and press the PLAY button. The tape will be loaded into the Deck Mechanism Ass embly. Make sure the power is on, connect TP507 (SENSOR INHIBITION) to GND. This will stop the functio n of Tape Start Sensor, Tape End Sensor and Reel Sensors . (If these TPs are connected before plugging in the unit, the function of the sensors will stay valid.) See Fig. 1.

Note: Because the Tape End Sensors are inactive, do not run a tape all the way to the start or the end of the tape to avoid tape damage.

Q504

Q505

TP507

S-INH

Fig. 1

1-5-1 HE274PFS

)

PWR. REC

10 11

12 13

OPERATING CONTROLS AND FUNCTIONS

[ VR340/55 ]

Front Panel

STANDBY/ON

Indicator

Rear Panel

CHANNEL

STOP/EJECT

987 456

FWD.PLAYREW.RECORD

16 17 18

AUDIO

AERIAL

OUT IN

RF OUT

VIDEO

21 20 19

1. STANDBY/ON button

2. Cassette compartment

[ / ] ( STOP/EJECT) button

4. [ ] (FWD)button ](PLAY) button

5. [

6. [ ](REW) button

7. RECORD button

8. Display window (See below

9. CHANNEL ( / ) buttons

10. PWR. (Power) indicator

11. TAPE IN indicator

12. REC indicator

13. (Timer) indicator

14. CLOCK indicator

15. AC power cord

16. AUDIO OUT jack

17. AUDIO IN jack

18. AERIAL terminal

19. RF OUT terminal

20. VIDEO IN jack

21. VIDEO OUT jack

Remote Control

EJECT

1 2

3 4

STANDBY/ON

MENU STATUS CLEAR

1 2 3

4 5 6

7 8

MEMORY ALT.CH

RECORD/OTR

STILL

6 7

8 9

NOTE

You can use this remote control to operate some PHILIPS TVs. Press [VCR] before pressing VCR feature buttons; press [TV] before pressing TV feature buttons if you have a PHILIPS TV .

CH. VOL.

MUTE

VCR TV

SPEED/SYSTEM

11 12 13

14 15

16 17

18 19

1. EJECT button

2. MENU button

3. NUMBER buttons

4. MEMORY button

5. [

( ) ](PLAY) button

6. RECORD/OTR button

7. [ (

) ](REW) button

8. MUTE button

9. CH(annel). buttons

10. VCR button

12. STATUS button

13. CLEAR button

14. ALT.CH.button

15. STILL button

16. [ (

) ](F .FWD)

button

17. [

( ) ](STOP) button

18. VOL(ume) buttons

19. TV button

SPEED/SYSTEM button

20.

11. STANDBY/ON button

To insert the batteries

Install two R6 batteries matching the polarity indicated inside the battery compartment.

CAUTION

On Battery Replacement

Do not mix old and new batteries. (Also never mix alkaline batteries with manganese batteries.)

1-6-1 HE274IB

[ VR340/75 ]

NOTE

You can use this remote control to operate some PHILIPS TVs. Press [VCR] before pressing VCR feature buttons; press [TV] before pressing TV feature buttons if you have a PHILIPS TV .

To insert the batteries

Install two R6 batteries matching the polarity indicated inside the battery compartment.

CAUTION

On Battery Replacement

Do not mix old and new batteries. (Also never mix alkaline batteries with manganese batteries.)

1-6-2 HE274IB

)

PWR. REC

13 14

15 16

[ VR740/55 ]

Front Panel

STANDBY/ON

VIDEO

L-AUDIO-R

Indicator

Rear Panel

CHANNEL

987456

19 20 21

FWD.PLAYREW.RECORD

AUDIO

OUT

AERIAL

VIDEO

RF OUT

OUT IN

22 23 24

STOP/EJECT

1. STANDBY/ON button

2. Cassette compartment

[ / ] ( STOP/EJECT) button

4. [ ] (F.FWD)button

5. [

](PLAY) button

6. [ ](REW) button

7. RECORD button

8. Display window (See below

9. CHANNEL ( / ) buttons

10.A/V CONNECTORS

13. PWR. (Power) indicator

14. TAPE IN indicator

15. REC indicator

16. (Timer) indicator

17. CLOCK indicator

18. AC power cord

19. AUDIO OUT jacks

20. AUDIO IN jacks

21. AERIAL terminal

22. VIDEO OUT jack

23. VIDEO IN jack

24. RF OUT terminal

Remote Control

EJECT

1 2

3 4

STANDBY/ON

MENU STATUS CLEAR

1 2 3

4 5 6

7 8

MEMORY ALT.CH

RECORD/OTR

STILL

6 7

8 9

NOTE

You can use this remote control to operate some PHILIPS TVs. Press [VCR] before pressing VCR feature buttons; press [TV] before pressing TV feature buttons if you have a PHILIPS TV .

CH. VOL.

MUTE

VCR TV

SPEED/SYSTEM

TIME SEARCH

AUDIO SELECT

SLOW

12 13 14

15 16

17 18

19 20

21 22 23

To insert the batteries

Install two R6 batteries matching the polarity indicated inside the battery compartment.

CAUTION

On Battery Replacement

Do not mix old and new batteries. (Also never mix alkaline batteries with manganese batteries.)

1-6-3 HE274IB

[ VR740/75 ]

NOTE

You can use this remote control to operate some PHILIPS TVs. Press [VCR] before pressing VCR feature buttons; press [TV] before pressing TV feature buttons if you have a PHILIPS TV .

To insert the batteries

Install two R6 batteries matching the polarity indicated inside the battery compartment.

CAUTION

On Battery Replacement

Do not mix old and new batteries. (Also never mix alkaline batteries with manganese batteries.)

1-6-4 HE274IB

SIGNAL NAME ABBREVIATIONS

Signal Name Function

4.43MHz 4.43MHz Clock A-COM Audio Head Common A-IN Audio Signal Input A-MODE Hi-Fi Tape Detection Signal

A-MUTE-H A-OUT Audio Signal Output A-PB/REC AE-H Audio Erase Head AFC

AL+12V

AL+5V AMPC CTL AMP Connected Terminal

AMPVcc AMPVcc AMPVREF

OUT AMPVREF AMPVss AMPVss

AVcc C-CONT Capstan Motor Control Signal C-F/R

C-FG

Audio Mute Control Signal (Mute = “H”)

Normal Audio Play Back/Record Signal

Automatic Frequency Control Signal

Always +12V with AC Plug Connected

Always +5V with AC Plug Connected

V-Ref for CTL AMP

IN V-Ref for CTL AMP

A/D Converter Power Input/ Standard Voltage Input

Capstan Motor FWD/REV Control Signal (FWD=”L”/REV=”H”)

Capstan Motor Rotation Detection Pulse

Signal Name Function

D-PFG

Drum Motor Phase/Frequency

Generator D-REC-H Delayed Record Signal D-V- SYNC Dummy V-sync Output DRV-CLK LED Clock Driver IC Control Clock DRV-DATA LED Clock Driver IC Control Data

DRV-STB

LED Clock Driver IC Chip Select

Signal END-S Tape End Position Detect Signal FE-H GND Ground for Full Erase Head

FF/REW-L FSC-IN

[4.43MHz ]

CTL Frequency Characteristics

Switching Signal (FF/REW=”L”)

4.43MHz Clock Input

H-A-COMP Head Amp Comparator Signal H-A-SW Video Head Amp Switching Pulse Hi-Fi-A Hi-Fi Audio Head Hi-Fi-COM Hi-Fi Audio Head Common HiFi-H-SW HiFi Audio Head Switching Pulse

HLF

C BUS- SCL I2C BUS Control Clock

C BUS- SDA I2C BUS Control Data

LPF Connected

Terminal (Slicer)

KEY-1 Key Scan Input Signal 1 KEY-2 Key Scan Input Signal 2

LD-SW

Deck Mode Position Detector

Signal LM-FWD/REV Loading Motor Control Signal

C-ROTA

Color Phase Rotary Changeover

SIgnal C-SYNC Composite Synchronized Pulse CLKSEL Clock Select (GND)

SECAM or MESECAM Chroma

COLOR-IN

Video Input Signal at Super Impose

CTL (+)

CTL (-)

Playback/Record Control Signal

(+)

Playback/Record Control Signal (-

) CTLAMPout To Monitor for CTL AMP Output D-CONT Drum Motor Control Signal

MOD-A Modulator Audio Output Signal N-A-PB Normal Audio Playback N-A-REC Normal Audio Recording

IN Clock Input for letter size

OSC

OUT Clock Output for letter size

OSC OSD-V-IN OSD Video Signal Input OSD-V-OUT OSD Video Signal Output OSDVcc OSDVcc OSDVss OSDVss

P-DOWN-L

Power Voltage Down Detector Signal

1-7-1 HE274SNA

Signal Name Function

P-OFF-H Power Off at High P-ON+5V +5V at Power-On Signal P-ON-L Power On Signal at Low P80/C P80/C Terminal

PG-DELAY

POW-SAF

REC-SAF-SW

REMOCON-IN Remote Control Sensor RESET System Reset Signal (Reset=”L”) RESET +5V +5V at System Reset Signal RF-SW Video Head Switching Pulse SIF Intermediate Frequency

ST-S T-REEL Take Up Reel Rotation Signal

TIMER+5V +5V at Timer TU-AUDIO Tuner Audio Input Signal TU-VIDEO Tuner Video Input Signal

TUN-SW1

Video Head Switching Pulse

Signal Adjusted Voltage

P-ON Power Detection Input

Signal

Recording Safety SW Detect (With

Record tab="L"/With out Record

tab="H")

Tape Start Position Detector

Signal

Tuner System Control Signal Output

TUN-SW2

V-ENV V-IN Video Signal Input

V-OUT Video Signal Output Vcc Vcc VIDEO Video Signal Vss Vss(GND) X-IN Main Clock Input X-OUT Main Clock Input XC-IN Sub Clock XC-OUT Sub Clock

Tuner System Control Signal Output

Video Envelope Comparator

Signal

1-7-2 HE274SNA

CABINET DISASSEMBLY INSTRUCTIONS

Comparison Chart of Models and Marks

Model Mark

VR340/55 A VR340/75 B VR740/55 C VR740/75 D

1. Disassembly Flowchart

This flowchart indicates the disassem bly steps to gain access to item(s) to be serviced. When reassembling, follow the steps in reverse order. Bend, route, and dress the cables as they were originally.

[1] Top Case

[2] Front Assembly

[3] VCR Chassis Unit

[4] Deck Assembly

[5] Main CBA

(1): Identification (location) No. of parts in the figures (2):Name of the part (3):Figure Number for reference (4): Identification of parts to be removed, unhooked,

unlocked, released, unplugged, unclamped, or desoldered. P=Spring, L=Locking Tab, S=Screw, CN=Connector *=Unhook, Unlock, Release, Unplug, or Desolder e.g. 2(S-2) = two Screws (S-2), 2(L-2) = two Locking Tabs (L-2)

(5):Refer to “Reference Notes.”

Reference Notes

CAUTION: Locking Tabs (L-1) and (L-2) are fragile. Be careful not to break them.

1. Remove five Screws (S-2), two Screws (S-3) and Screw (S-4). Then, slowly lift the VCR Chassis Unit (Deck Assembly, Jack CBA and Main CBA) up.

2. When reassembling, solder wire jumpers as shown in Fig. 5.

3. Before installing the Deck Assembly, be sure to place the pin of LD-SW on Main CBA as sho wn in Fig. 6. Then, install the Deck Assembly while aligning the hole of Cam Gear with the pin of LD-SW, the shaft of Cam Gear with the hole of LD-SW as shown in Fig. 6.

2. Disassembly Method

REMOVAL

ID/

LOC.

No.

[1] Top Case 1 3(S-1) -

[2]

[3]

[4]

[5] Main CBA 4,5 ---------- -

↓

(1)

PART

Front Assembly

VCR Chassis Unit

Deck Assembly

↓

(2)

REMOVE/*UNHOOK/

Fig.

UNLOCK/RELEASE/

No.

UNPLUG/DESOLDER

2 *3(L-1),*4(L-2) -

5(S-2) ,

2(S-3)---[Mark: C, D]

3(S-4), 2(W-1),

4,5

Desolder

↓

(3)

↓

(4)

(S-1)

Note

[1] T op Case

2,3

↓

(5)

Fig. 1

1-8-1 HE274DC

(L-2)

FE Head

Cylinder Assembly

[2] Front Assembly

[3]VCR Chassis Unit

(S-3)

(L-1)

(S-2)

Fig. 2

[4] Deck Assembly

[5] Main CBA

From Capstan Motor Assembly

(W-1)

(S-4)

From ACE Head Assembly

(S-4)

From Cylinder Assembly

ACE Head Assembly

(W-1)

(S-4)

From FE Head

[ C,D ]

(S-3)

[ C,D ]

Fig. 3

Printing side

Desolder

Lead connections of Deck Assembly and Main CBA

Lead with blue stripe

Desolder

BOTT OM VIEW

Lead with blue stripe

Fig. 4

1-8-2 HE274DC

[5] Main CBA

[4] Deck Assembly

SW507 LD-SW

Cam Gear

LD-SW

Shaft

Hole

[5] Main CBA

Fig. 5

1-8-3 HE274DC

ELECTRICAL ADJUSTMENT INSTRUCTIONS

)

C C

General Note: "CBA" is an abbreviation for "Circuit Board Assembly."

NOTE:

1.Electrical adjus tments are required after replacing circuit components a nd certain mechanical parts. It is important to do these a djustments only after all repairs and replacements have been completed. Also, do not attempt these adjustments unless the proper equipment is available.

2.To perform these alignment / confirmation procedures, make sure that the tracki ng co ntrol is set in the center position: P ress eith er "L5??" or "K" button on the remote control unit first, then the "PLAY" button (Front Panel only).

Test Equipment Required

1.Oscilloscope: Dual-trace with 10:1 probe, V-Range: 0.001~50V/Div., F-Range: DC~AC-20MHz

2.Alignment Tape (4822 395 10283)

Head Switching Position Adjustment

Purpose:

To determine the Head Switching point during playback.

Symptom of Misadjustment:

May cause Head Switching noise or ver tical jitter in the picture.

Test point Adj.Point Mode Input

TP751(V-OUT)

TP502(RF-SW)

GND

Tape

4822 395 10283 Oscilloscope

Connections of Measurement Equipment

TP751

Main CBA

TP502

VR501

(Switching Point)

(MAIN CBA)

Measurement

Equipment

GND

PLAY

(SP)

6.5H±1H

(412.7µs±60µs)

Oscilloscop

-----

Spec.

CH1 CH Trig. (+

Figure 1

EXT. Syncronize Trigger Point

V-Syn

H1 H2

Reference Notes: Playback the Alignment tape and adjust VR501 so that the V-sync front edg e of the CH1 video output waveform is at the 6.5H(412.7µs) delayed position from the rising edge of the CH2 head switching pulse waveform.

1.0H

Switching Pulse

6.5H

0.5H

1-9-1 HE274EA

Adjustment Points and Test Points

Main CBA Top View

TP751 V-OUT

TP301 C-PB

TUNER BLOCK

TP502 RF-SW

VR501 SW-P

Hi-Fi BLOCK

VIDEO BLOCK

SYSCON/TIMER SERVO BLOCK

TEST POINT INFORMATION

: Indicates a test point with a jumper wire across a hole in the PCB.

TEST POINTS NOT USED IN ELECTRICAL ADJUSTMENTS

Test Point

TP301 TP501 TP507

Mechanical Alignment Procedures Mechanical Alignment Procedures Preparation for Servicing

Used in: Page No.

AUDIO BLOCK

2-3-3, 2-3-4 2-3-3, 2-3-4

1-5-1

POWER SUPPLY BLOCK

POWER CTL BLOCK

TP507 SENS-INH

Comparison Chart of Models and Marks

Model Mark

VR340/55 VR340/75 VR740/55 VR740/75

TP501

CTL

A B C D

[ A, B ] [ C, D ]

Main CBA

Audio Out

Audio Out (R)

Audio In

Video Out

Video In

Tuner Unit

Antenna In Antenna Out

Audio In (R)

Video Out

Video In

Audio Out (L)

Main CBA

Audio In (L)

Tuner Un

Antenna In Antenna Out

1-9-2 HE274EA

Servo/System Control Block Diagram

Comparison Chart of Models & Marks

Model Mark

VR340/55 VR340/75 VR740/55 VR740/75 D

Q504

ST-S

SENSOR CBA

Q505

END-S

A B C

" " = SMD

MAIN CBA

TP505

ST-S

BLOCK DIAGRAMS

NOTE FOR WIRE CONNECTORS:

1. PREFIX SYMBOL "CN" MEANS CONNECTOR. (CAN DISCONNECT AND RECONNECT.)

2. PREFIX SYMBOL "CL" MEANS WIRE-SOLDER HOLES OF THE PCB. (WIRE IS SOLDERED DIRECTLY.)

AL+5V

SW507 LD-SW

AL+5V

Q503

T-REEL

D502 S-LED

TIMER+5V

C,D

TP501

CTL

Q502

RESET

Q501

TEST POINT INFORMATION

:INDICATES A TEST POINT WITH A JUMPER WIRE ACROSS A HOLE IN THE PCB. :USED TO INDICATE A TEST POINT WITH A COMPONENT LEAD ON FOIL SIDE. :USED TO INDICATE A TEST POINT WITH NO TEST PIN. :USED TO INDICATE A TEST POINT WITH A TEST PIN.

IC501

(SERVO/SYSTEM CONTROL)

CTL AMP OUT

FF/REW-L84

LD-SW9

CTL(+) CTL(-)

94 10

ST-S

END-S T-REEL

RESET

KEY- 1

KEY- 2

DRV-DATA

DRV-STB DRV-CLK

68 69 70

C,D

CL509

KEY SWITCH

IC561

(LED DISPLAY)

DRV-DATA

DRV-STB

DRV-CLK

TP507

SENS-INH

1 POWER

CL511

1 STOP/EJECT

FP562

LED DISPLAY

SW1 CBA

KEY SWITCH

SW2 CBA

KEY SWITCH

SENSOR CBA

(DECK ASSEMBLY)

CONTROL HEAD

AC HEAD ASSEMBLY

CYLINDER ASSEMBLY CAPSTAN MOTOR

PG SENSOR

DRUM MOTOR

LOADING MOTOR

CL287

5 5CTL(+) 6 6CTL(-)

CL504

CAPSTAN MOTOR

VR501 SW-POINT

CL502

12 AL+15V 11

AL+12V(2)

10 GND

D-PFG

D-CONT

LM-FWD/REV

GND

C-CONT

C-F/R

C-FG

AL+5V

AL+12V

AL+5V

FROM/TO POWER SUPPLY BLOCK

AL+5V

AL+15V AL+12V

AL+5V AL+12V

P-ON-L P-DOWN-L

P-OFF-H

SW506 REC-

SAFETY

PG-DELAY

RECSAF-SW

D-PFG

D-CONT77 LM-

FWD/REV

C-CONT

C-F/R

C-FG

P-ON-L

P-DOWN-L

P-OFF-H

REMOCON-IN

A-MUTE-H

C,D

Hi-Fi-H-SW

A-MODE

IIC-BUS SDA

IIC-BUS SCL

D-REC-H

C-ROTA

D-V SYNC

H-A-SW

H-A-COMP

C,D

C-SYNC

RF-SW

V-ENV

19 32

72 71

33 18 15

S10

RS501

REMOTE SENSOR

TU701(TUNER UNIT)

SDA

SCL

IC503 (MEMORY)

SDA

SCL

D-REC-H

IIC-BUS SDA

IIC-BUS SCL

A-MUTE-H

IIC-BUS SDA

IIC-BUS SCL

Hi-Fi-H-SW

A-MODE

A-MUTE-H

IIC-BUS SDA

IIC-BUS SCL

D-REC-H

RF-SW

C-ROTA

D-V SYNC

H-A-SW

H-A-COMP

V-ENV

C-SYNC

TO AUDIO BLOCK

FROM/TO Hi-Fi AUDIO BLOCK

FROM/TO VIDEO BLOCK

1-10-1 1-10-2 HE274BLS

Video Block Diagram

" " = SMD

REC-VIDEO SIGNAL PB-VIDEO SIGNAL MODE: SP/REC

TP751

V-OUT

WF1

JK751 V-OUT

TU701

VIDEO

BUFFER

Q305

IC501 (OSD)

OSD CHARACTER

MIX

IC301

(Y/C PROCESS)

COLOR

-IN

NOTE FOR WIRE CONNECTORS:

1. PREFIX SYMBOL "CN" MEANS CONNECTOR. (CAN DISCONNECT AND RECONNECT.)

2. PREFIX SYMBOL "CL" MEANS WIRE-SOLDER HOLES OF THE PCB. (WIRE IS SOLDERED DIRECTLY.)

MAIN CBA

A,C

29 67 66 49

AMP

X302

4.43MHz

VXO

TEST POINT INFORMATION

Q307

BUFFER

CCD 1H

DELAY

46 41

CLAMP

Q304

BUFFER

CLAMP

21 24 2320

SERIAL

DECORDER

IIC-BUS SDA

IIC-BUS SCL

Comparison Chart of Models & Marks

FROM/TO SERVO/SYSTEM CONTROL BLOCK

Model Mark

VR340/55 VR340/75 VR740/55 VR740/75 D

A B C

TU-VIDEO

JK753 V-IN-F

JK752 V-IN

FROM/TO SERVO /SYSTEM CONTROL BLOCK

D-REC-H C-SYNC D-V SYNC

BUFFER

Q308

TUNER

36 38

LINE

D-REC-H

C-SYNC

D-V SYNC

32 31

AGC

R P

BPF

D.E.

FBC

R P

1/2

NOISE

CANCELMDE EMPA

Y/C MIX

PIC-CTL

ANR

C-COMB COMB

Y-LPF

72715759 54 52 51 61

KIL

AMP

DOC YNR Y/C COMB

MAPBPF

KILL B.D.

CCD

LPF

R P

ACC

4.43MHz

B-UP AMP

DETAIL

ENH

W/D CLIP

CONV

629KHz

BPF

MAIN

CONV

SUB

R P

MOD

V/I

CONV

FM-EQ

C-LPF

REC

SUB

LPF

REC FM

AGC

DEMOD.

PB FM

AGC

DOUBLE

LIMIT

FM-EQ

EMPHA

Q302, Q303

PEAKING AMP

(DECK ASSEMBLY)

CYLINDER ASSEMBLY

VIDEO (R)-1 HEAD

VIDEO (L)-1 HEAD

VIDEO (L)-2 HEAD

VIDEO (R)-2 HEAD

C,D

WF2

C-ROTA

H-A-COMP

H-A-SW

V-ENV

RF-SW

TP301

C-PB

FROM/TO SERVO/SYSTEM CONTROL BLOCK

1 2 3 4 5 6

CL253

V(R)-1

V-COM V(L)-1

V(L)-2

V-COM V(R)-2

C-ROTA

COMP

OUT

C,D

93 11

R L

ENV DET

TP502

RF-SW

WF3

1-10-3 1-10-4 HE274BLV

Audio Block Diagram

NOTE FOR WIRE CONNECTORS:

" " = SMD

REAR

TU701

A-OUT (L)

A,B

A-OUT

A-OUT (R)

C,D

A,B

A-IN

C,D

A-IN (L)

A-IN (R)

A-IN (L)-F

AUDIO OUT

1. PREFIX SYMBOL "CN" MEANS CONNECTOR. (CAN DISCONNECT AND RECONNECT.)

2. PREFIX SYMBOL "CL" MEANS WIRE-SOLDER HOLES OF THE PCB. (WIRE IS SOLDERED DIRECTLY.)

SIF OUT

AUDIO IN

2 2

JK751

JK752

JK754

CN701 CN1

TP754 A-OUT(L)

SIF

TP752 A-OUT(R)

TEST POINT INFORMATION

AFV CBA

IF SIGNAL PROCESS

TU-AUDIO(R) TU-AUDIO(L)

Comparison Chart of Models & Marks

Model Mark

VR340/55 VR340/75 VR740/55

PB-AUDIO SIGNAL REC-AUDIO SIGNAL Mode : SP/REC

VR740/75 D

MAIN CBA

CN701CN1

4 5

J928

J919

IC301

(AUDIO PROCESS)

J917

C,D

TUNER LINE

A,B

J916

A,B

J926

TU-AUDIO(R)

TU-AUDIO(L)

MOD-A

A-IN (L)

A-IN (R)

A-IN (L)-F A-IN (R)-F A-OUT (L)

A-OUT (R)

N-A-REC

N-A-PB

J918J24

A B C

FROM/TO Hi-Fi AUDIO BLOCK

C,D

FRONT

A-IN (R)-F

(DECK ASSEMBLY)

AUDIO HEAD

AUDIO ERASE HEAD

FULL ERASE HEAD

JK755

C,D

ACE HEAD ASSEMBLY

CN287 A-PB/REC 4 A-COM 3 AE-H 1 AE-H/FE-H 2

FE HEAD

CL504 4 A-PB/REC 3 A-COM 1 AE-H 2 AE-H/FE-H

CL501 2 FE-H 1 FE-H-GND

Q402

BIAS OSC

Q404 (PB=ON)

Q405 (PB=ON)

Q403

4 3

Q401

AL+5V

SWITCHING D-REC-OFF

AL+5V

PB-ON

EQ AMP

SP/LP-ON

AUTO BIAS

ALC

100

REC AMP

LINE AMP

MUTE

SERIAL

DECODER

23 24

IIC-BUS SDA IIC-BUS SCL

A-MUTE-H

D-REC-H

TO SERVO/SYSTEM CONTROL BLOCK

1-10-5 1-10-6 HE274BLA

Hi-Fi Audio Block Diagram ( C, D )

NOTE FOR WIRE CONNECTORS:

1. PREFIX SYMBOL "CN" MEANS CONNECTOR. (CAN DISCONNECT AND RECONNECT.)

" " = SMD

2. PREFIX SYMBOL "CL" MEANS WIRE-SOLDER HOLES OF THE PCB. (WIRE IS SOLDERED DIRECTLY.)

IC451 (MTS/ SAP/ Hi-Fi AUDIO PROCESS/ Hi-Fi HEAD AMP)

TEST POINT INFORMATION

MAIN CBA

Comparison Chart of Models & Marks

Model Mark

VR340/55 VR340/75 VR740/55 VR740/75 D

REC-AUDIO SIGNALPB-AUDIO SIGNAL Mode : SP/REC

A B C

TO AUDIO BLOCK

A-IN(R) TU-AUDIO(R) A-IN(R)-F

A-IN(L) TU-AUDIO(L) A-IN(L)-F

N-A-REC

N-A-PB

52 44 49

SERIAL DATA DECODER

R-CH INSEL

NOR SW

L-CH

INSEL

46 45

4 5

ALC

R-CH PNR

L-CH PNR

SW NOISE

LIM DEV

SW NOISE

COMP

VCO

HOLD PULSE

NOISE DET

VCO

COMP

LPF

MIX

LPF

R-CH BPF

OUTPUT SELECT

COMP AMP

L-CH BPF

AGC

AGC DET

ALC MUTE

BIAS

18 19

OD DET

ENV DET

31 32

57 56

IIC-BUS SDA

IIC-BUS SCL

A-MUTE-H

Hi-Fi-SW

A-MODE

A-OUT(L)

MOD-A

A-OUT(R)

CN253

Hi-Fi-A(R) 7 Hi-Fi-COM 8 Hi-Fi-A(L) 9

FROM/TO SERVO/ SYSTEM CONTROL BLOCK

TO AUDIO BLOCK

Hi-Fi AUDIO (R) HEAD

Hi-Fi AUDIO (L) HEAD

CYLINDER ASSEMBLY

HE494BLH1-10-7 1-10-8

Power Supply Block Diagram

Comparison Chart of Models & Marks

Model Mark

VR340/55 VR340/75 VR740/55 VR740/75 D

A B C

AC001

NOTE : The voltage for parts in hot circuit is measured using hot GND as a common terminal.

HOT CIRCUIT. BE CAREFUL.

F001 T1.6A L 250V

L003

LINE FILTER

D001 - D004

BRIDGE RECTIFIER

CAUTION

FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH THE SAME TYPE T1.6AL/250V FUSE.

T001

Q001

Q059

C,D

CAUTION !

Fixed voltage (or Auto voltage selectable ) power supply circuit is used in this unit. If Main Fuse (F001) is blown, check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply. Otherwise it may cause some components in the power supply circuit to fail.

MAIN CBA

AL+15V AL+32V P-ON-L AL+12V P-ON+9V

Q053

C,D

Q054

C,D

AL+5V P-ON+5V TIMER+5V P-DOWN-L P-OFF-H

Q003

HOT

Q002

IC001

ERROR VOLTAGE DET

Q004 SHUNT

REGULATOR

REG

Q055

Q056

Q057

COLD

1-10-9 1-10-10

HE274BLP

(

SCHEMATIC DIAGRAMS / CBA'S AND TEST POINTS

Standard Notes WARNING

Notes:

1. Do not use the part n umber shown on thes e drawings for ordering. The correct part number is

Many electrical and mechanical parts in this chassis have special characteristics. These characteristics often pass unnoticed and the protection afforded by them cannot nece ssar ily b e ob tai ned by us ing repl ac ement components rated for higher voltage, wattage, etc. Replacement parts that have th ese spe cial safety characteristics are identified in this manual and its supplements; electrical comp onents having such features are identified by the mark " ! " in the schematic diagram and the parts list. Before replacing any of these components, read the parts list in this manual carefully. The use of substitute replacement parts that do not have the same s afety character istics as specified in the parts list may create shock, fire, or other hazards.

Capacitor Temperature Markings

Mark

(B)

Capacity

change rate

±10%

Standard

Temperature

temperature

20°C -25~+85°C

range

(F) +30 - 80% 20°C –25~+85°C

(SR)

±15%

20°C –25~+85°C

shown in the parts list, and may be slightly different or amended since these drawings were prepared.

2. To maintain original function and reliability of repaired units, use onl y original replace ment parts which are listed with the ir part numb ers i n the parts list section of the service manual.

3. Prefix symbol "CN" means "connector" (can disconnect and reconnect). Prefix symbol "CL" m ean s " wir e-s old er hol es of the PCB" (wire is soldered directly).

4. How to read converged lines.

-D3

Distinction Area Line Number (1 to 3 digits)

Examples:

AREA D3

AREA B1

1-D3

ABCD

1-B1

(1). "1-D3" means that line number "1" goes to area "D3."

(2). "1-B1" means that line number "1" goes to area "B1."

5. All resistance values are indicated in ohms

(Y)

±22.5%

Capacitors and transistor s are represented by the following symbols.

20°C –25~+85°C

(K=10

, M=106).

6. Resis tor wattages a re 1/4 W or 1/6W u nless other wise specified.

7. All capacitance values are indicated in µF

-6

(P=10

µF).

8. All voltages are DC voltages unless otherwise specified.

9. Voltage indications for PLAY and REC modes on the schematics are as shown below.

< PCB Symbols >

(Top View) (Bottom View)

Electrolytic Capacitor

Bottom View)

Transistor or Digital Transistor

E C B

(Top View)

NPN Transistor

(Top View)

PNP Transistor

(Unit: Volt)

The same voltage for both PLAY & REC modes.

5.0

< Schematic Diagram Symbols >

5.0 (2.5)

Indicates that the voltage is not consistent here.

Digital Transistor

PLAY mod REC mode

E C B

(Top View)

NPN Digital Transistor

E C B

(Top View)

PNP Digital Transistor

E C B

1-11-1 SC_08

+ 63 hidden pages

Philips VR340/55, VR740/55, VR340/75, VR740/75 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

MAIN SECTION

SPECIFICATIONS

IMPORTANT SAFETY PRECAUTIONS

STANDARD NOTES FOR SERVICING

FUNCTION INDICATOR SYMBOLS

PREPARATION FOR SERVICING

OPERATING CONTROLS AND FUNCTIONS

SIGNAL NAME ABBREVIATIONS

CABINET DISASSEMBLY INSTRUCTIONS

ELECTRICAL ADJUSTMENT INSTRUCTIONS

Adjustment Points and Test Points

BLOCK DIAGRAMS

SCHEMATIC DIAGRAMS / CBA'S AND TEST POINTS