JVC AV-20FD23 Service Manual

SERVICE MANUAL

TV/DVD COMBO

AV-20FD23

CATV

POWER

SUBTITLE

DVD

CONTROL

REPEATA-B

ZOOM

TITLE

RETURN

PLAY MODE

SLOW

AUDIO

ANGLE

123

CANCEL

456

DISPLAY

789

TV RETURN

C.C.

SLEEP TIMER

INPUT

AUDIO

LIGHT

RM-C394G

SELECT

MUTING

/ENTER

VOL

DVD SETUP

TV MENU

TV/DVD

DVD MENU

PREV NEXT

B.SEARCH

PLAY

F.SEARCH

OPEN/CLOSE

STOP

PAUSE/STILL

TV / DVD

a SPECIFICATIONS ....................................................................................................................................2

¤ OPERATING INSTRUCTIONS (APPENDED)

a SAFETY PRECAUTIONS ........................................................................................................................3

a SPECIFIC SERVICE INSTRUCTIONS ....................................................................................................8

a SERVICE ADJUSTMENTS ....................................................................................................................16

a GUIDE FOR REPAIRING .......................................................................................................................22

¤ STANDARD CIRCUIT DIAGRAM ........................................................................................................ 2-1

a PARTS LIST ...........................................................................................................................................33

No. 52014

May 2002

AV-20FD23

SPECIFICATIONS

TELEVISION

Picture Tube: 20” (measured diagonally)

Tuner Type: Quartz PLL Frequency Synthesized

Receiving Channels: VHF 2-13

UHF 14-69

CATV 14-36 (A)-(W)

37-59 (AA)-(WW)

60-85 (AAA)-(ZZZ)

86-94 (86)-(94)

95-99 (A-5)-(A-1)

100-125 (100)-(125)

01 (5A)

Antenna Input: VHF/UHF In 75 ohms coaxial

Speaker: 3”, 8 ohms x 2

Audio Output Power: 2.5 + 2.5 W

DVD/CD player

Signal system: NTSC

Applicable disc: 1. DVD (12cm, 8cm)

2. CD (12cm, 8cm)

Audio characteristics: DVD: 4Hz - 22KHz

Frequency response: CD: 4Hz - 20KHz

S/N Ratio: 90dB

Harmonic distortion: 0.06%

Wow and flutter: Below Measurable Level

Dynamic range: 96dB

Input/Output: Inputs : Video : (RCA) 1 Vp-p/75ohm

Audio : (RCA) –8 dB/50Kohm

Outputs : Video : (RCA) 1 Vp-p/75ohm

Audio : (RCA) –8 dB/1Kohm

GENERAL

Power Source: AC 120V 60Hz

Power Consumption: 110 Watts

Dimensions: W 22-5/8” x D 19-1/8” x H 20-3/8”

Weight: 56.1 Ibs/25.5 kg

Inputs: Video: In (RCA) 1Vp-p 75 ohm

Audio: In (RCA) -8 dB/50K ohm

Headphone Jack: 3.5mm mini-jack

Storage Temperature -20 °C ~ 60 °C

Operating Temperature 5 °C ~ 40 °C

Accessories:

Remote Control X 1

Batteries (AA) X 2

Design & specification are subject to change without notice.

2 No. 52014

SAFETY PRECAUTIONS

SERVICING NOTICES ON CHECKING

As for the places which need special attentions, they are indicated with the labels or seals on the cabinet, chassis and parts. Make sure to keep the indications and notices in the operation manual.

2. AVOID AN ELECTRIC SHOCK

There is a high voltage part inside. Avoid an electric shock while the electric current is flowing.

3. USE THE DESIGNATED PARTS

The parts in this equipment have the specific characters of incombustibility and withstand voltage for safety. Therefore, the part which is replaced should be used the part which has the same character. Especially as to the important parts for safety which is indicated in the circuit diagram or the table of parts as a mark, the designated parts must be used.

4. PUT PARTS AND WIRES IN THE ORIGINAL POSITION AFTER ASSEMBLING OR WIRING

There are parts which use the insulation material such as a tube or tape for safety, or which are assembled in the condition that these do not contact with the printed board. The inside wiring is designed not to get closer to the pyrogenic parts and high voltage parts. Therefore, put these parts in the original positions.

5. TAKE CARE TO DEAL WITH THE CATHODE-RAY TUBE

In the condition that an explosion-proof cathoderay tube is set in this equipment, safety is secured against implosion. However, when removing it or serving from backward, it is dangerous to give a shock. Take enough care to deal with it.

6. AVOID AN X-RAY1. KEEP THE NOTICES

Safety is secured against an X-ray by considering about the cathode-ray tube and the high voltage peripheral circuit, etc. Therefore, when repairing the high voltage peripheral circuit, use the designated parts and make sure not modify the circuit. Repairing except indicates causes rising of high voltage, and it emits an X-ray from the cathoderay tube.

PERFORM A SAFETY CHECK AFTER

7. SERVICING

Confirm that the screws, parts and wiring which were removed in order to service are put in the original positions, or whether there are the portions which are deteriorated around the serviced places serviced or not. Check the insulation between the antenna terminal or external metal and the AC cord plug blades. And be sure the safety of that.

(INSULATION CHECK PROCEDURE)

Unplug the plug from the AC outlet.

Remove the antenna terminal on TV and turn on the TV. Insulation resistance between the cord plug

terminals and the eternal exposure metal [Note 2] should be more than 1M ohm by using the 500V insulation resistance meter [Note 1].

If the insulation resistance is less than 1M ohm, the inspection repair should be required.

[Note 1]

If you have not the 500V insulation resistance meter, use a Tester.

[Note 2]

External exposure metal: Antenna terminal

Earphone jack

AV-20FD23

HOW TO ORDER PARTS

Please include the following informations when you order parts. (Particularly the VERSION LETTER.)

1. MODEL NUMBER and VERSION LETTER The MODEL NUMBER can be found on the back of each product and the VERSION LETTER can be

found at the end of the SERIAL NUMBER.

2. PART NO. and DESCRIPTION You can find it in your SERVICE MANUAL.

No. 52014 3

AV-20FD23

CAUTION

THIS DIGITAL VIDEO PLAYER EMPLOYS A LASER SYSTEM.

TO ENSURE PROPER USE OF THIS PRODUCT, PLEASE READ THIS SERVICE MANUAL CAREFULLY AND RETAIN FOR FUTURE REFERENCE. SHOULD THE UNIT REQUIRE MAINTENANCE, CONTACT AN AUTHORIZED SERVICE LOCATION-SEE SERVICE PROCEDURE.

USE OF CONTROLS, ADJUSTMENTS OR THE PERFORMANCE OF PROCEDURES OTHER THAN THOSE SPECIFIED HEREIN MAY RESULT IN HAZARDOUS RADIATION EXPOSURE.

TO PREVENT DIRECT EXPOSURE TO LASER BEAM, DO NOT TRY TO OPEN THE ENCLOSURE. VISIBLE LASER RADIATION MAY BE PRESENT WHEN THE ENCLOSURE IS OPENED. DO NOT STARE INTO BEAM.

Location of the required Marking

The rating sheet and the safety caution are on the rear of the unit.

CERTIFICATION: COMPLIES WITH FDA RADIATION PERFORMANCE STANDARDS, 21 CFR SUBCHAPTER J.

4 No. 52014

IMPORTANT SERVICE SAFETY INFORMATION

AV-20FD23

Operating the receiver outside of its cabinet or with its back removed involves a shock hazard. Work on these models should only be performed by those who are thoroughly familiar with precautions necessary when working on high voltage equipment.

Exercise care when servicing this chassis with power applied. Many B plus and high voltage RF terminals are exposed which, if carelessly contacted, can cause serious shock or result in damage to the chassis. Maintain interconnecting ground lead connections between chassis, escutcheon, picture tube dag and tuner cluster when operating the chassis.

These receivers have a "polarized" AC line cord. The AC plug is designed to fit into standard AC outlets in one direction only. The wide blade connects to the "ground side" and the narrow blade connects to the "hot side" of the AC line. This assures that the TV receiver is properly grounded to the house wiring. If an extension cord must be used, make sure it is of the "polarized" type.

Since the chassis of this receiver is connected to one side of the AC supply during operation, service should not be attempted by anyone not familiar with the precautions necessary when working on these types of equipment.

When it is necessary to make measurements or tests with AC power applied to the receiver chassis, an Isolation Transformer must be used as a safety precaution and to prevent possible damage to transistors. The Isolation Transformer should be connected between the TV line cord plug and the AC power outlet.

Certain HV failures can increase X-ray radiation. Receivers should not be operated with HV levels exceeding the specified rating for their chassis type. The maximum operating HV specified for the chassis used in these receivers is 32kV±1.0kV at zero beam current with a line voltage of 120V AC. Higher voltage may also increase the possibility of failure in the HV supply.

The picture tube used in this receiver employs integral implosion protection. Replace with a tube of the same type number for continued safety. Do not lift picture tube by the neck. Handle the picture tube only when wearing shatterproof goggles and after discharging the high voltage completely. Keep others without shatterproof goggles away.

When removing springs or spring mounted parts from the tuner, tuner cluster or chassis, shatterproof goggles must be worn. Keep others without shatterproof goggles away.

Before returning the receiver to the user, perform the following safety checks:

Inspect all lead dress to make certain that leads are not pinched or that hardware is not lodged between the chassis and other metal parts in the receiver.

Replace all protective devices such as nonmetallic control knobs, insulating fishpapers, cabinet backs, adjustment and compartment covers or shields, isolation resistor-capacitor networks, mechanical insulators, etc.

To be sure that no shock hazard exists, a check for the presence of leakage current should be made at each exposed metal part having a return path to the chassis (antenna, cabinet metal, screw heads, knobs and/or shafts, escutcheon, etc.) in the following manner.

Plug the AC line cord directly into a 120V AC receptacle. (Do not use an Isolation Transformer during these checks.) All checks must be repeated with the AC line cord plug connection reversed. (If necessary, a nonpolarized adapter plug must be used only for the purpose of completing these checks.)

If available, measure current using an accurate leakage current tester. Any reading of 0.35mA or more is excessive and indicates a potential shock hazard which must be corrected before returning the receiver to the owner.

It is important to maintain specified values of all components in the horizontal and high voltage circuits and anywhere else in the receiver that could cause a rise in high voltage, or operating supply voltages. No changes should be made to the original design of the receiver.

Components shown in the shaded areas on the schematic diagram and/or identified by

in the replacement parts list should be replaced only with exact factory recommended replacement parts. The use of unauthorized substitute parts may create shock, fire, Xray radiation, or other hazards.

To determine the presence of high voltage, use an accurate high impedance HV meter connected between the second anode lead and the CRT dag grounding device. When servicing the High Voltage System, remove static charges from it by connecting a 10k ohm resistor in series with an insulated wire (such as a test probe) between the picture tube dag and 2nd anode lead (have AC line cord disconnected from AC supply).

If a reliable leakage current tester is not available, this alternate method of measurement should be used. Using two clip leads, connect a 1500 ohm, 10 watt resistor paralleled by a 0.15µF capacitor in series with a known earth ground, such as a water pipe or conduit and the metal part to be checked. Use a VTVM or VOM with 1000 ohms per volt, or higher, sensitivity to measure this AC voltage drop across the resistor. Any reading of 0.35 volt RMS or more is excessive and indicates a potential shock hazard which must be corrected before returning the receiver to the owner.

VT VM

AC SCALE

1.5K OHMS 10W

15µF

TO EXPOSED METAL PARTS

TEST PROBE

TO KNOWN EARTH GROUND

No. 52014 5

AV-20FD23

IMPORTANT SAFEGUARDS

READ INSTRUCTIONS

All the safety and operating instructions should be read before the unit is operated.

RETAIN INSTRUCTIONS

The safety and operating instructions should be retained for future reference.

HEED WARNINGS

All warnings on the unit and in the operating instructions should be adhered to.

FOLLOW INSTRUCTIONS

All operating and use instructions should be followed.

CLEANING

Unplug this unit from the wall outlet before cleaning. Do not use liquid cleaners or aerosol cleaners. Use a damp cloth for cleaning.

ATTACHMENTS

Do not use attachments not recommended by the unit’s manufacturer as they may cause hazards.

WATER AND MOISTURE

Do not use this unit near water. For example, near a bathtub, washbowl, kitchen sink, or laundry tub, in a wet basement, or near a swimming pool.

ACCESSORIES

Do not place this unit on an unstable cart, stand, tripod, bracket, or table. The unit may fall, causing serious injury, and serious damage to the unit. Use only with a cart, stand, tripod, bracket, or table recommended by the manufacturer. An appliance and cart combination should be moved with care. Quick stops, excessive force,

8A.

and uneven surfaces may cause the appliance and cart combination to overturn.

VENTILATION

Slots and openings in the cabinet and in the back or bottom are provided for ventilation, to ensure reliable operation of the unit, and to protect it from overheating. These openings must not be blocked or covered. The openings should never be blocked by placing the unit on a bed, sofa, rug, or other similar surface. This unit should never be placed near or over a radiator or heat source . This unit should not be placed in a built-in installation such as a bookcase or rack unless proper ventilation is provided or the manufacturer’s instructions have been adhered to.

POWER SOURCES

10.

This unit should be operated only from the type of power source indicated on the rating plate. If you are not sure of the type of power supply to your home, consult your appliance dealer or local power company. For units intended to operate from battery power, or other sources, refer to the operating instructions.

GROUNDING OR POLARIZATION

11.

This unit is equipped with a polarized alternating-current line plug (a plug having one blade wider than the other). This plug will fit into the power outlet only one way. This is a safety feature. If you are unable to insert the plug fully into the outlet, try reversing the plug. If the plug should still fail to fit, contact your electrician to replace your obsolete outlet. Do not defeat the safety purpose of the polarized plug. If your unit is equipped with a 3-wire grounding-type plug, a plug having a third (grounding) pin, this plug will only fit into a grounding-type power outlet. This too, is a safety feature. If you are unable to insert the plug into the outlet, contact your electrician to replace your obsolete outlet. Do not defeat the safety purpose of the grounding-type plug.

12.

POWER-CORD PROTECTION

Power-supply cords should be routed so that they are not likely to be walked on or pinched by items placed upon or against them, paying particular attention to cords at plugs, convenience receptacles, and the point where they exit from the appliance.

13.

LIGHTNING

To protect your unit from a lightning storm, or when it is left unattended and unused for long periods of time, unplug it from the wall outlet and disconnect the antenna or cable system. This will prevent damage to the unit due to lightning and power line surges.

14.

POWER LINES

An outside antenna system should not be located in the vicinity of overhead power lines or other electric light or power circuits, or where it can fall into such power lines or circuits. When installing an outside antenna system, extreme care should be taken to keep from touching such power lines or circuits, as contact with them might be fatal.

15.

OVERLOADING

Do not overload wall outlets and extension cords, as this can result in a risk of fire or electric shock.

16.

OBJECT AND LIQUID ENTRY

Do not push objects through any openings in this unit, as they may touch dangerous voltage points or short out parts that could result in fire or electric shock. Never spill or spray any type of liquid into the unit.

17.

OUTDOOR ANTENNA GROUNDING

If an outside antenna or cable system is connected to the unit, be sure the antenna or cable system is grounded so as to provide some protection against voltage surges and built-up static charges. Section 810 of the National Electrical Code, ANSI/NFPA 70, provides information with respect to proper grounding of the mast and supporting structure, grounding of the lead-in wire to an antenna discharge unit, size of grounding conductors, location of antenna discharge unit, connection to grounding electrodes, and requirements for the grounding electrode.

18.

SERVICING

Do not attempt to service this unit yourself as opening or removing covers may expose you to dangerous voltage or other hazards. Refer all servicing to qualified service personnel.

AC)

PORTABLE CART WARNING

(symbol provided by RET

S3126A

6 No. 52014

AV-20FD23

IMPORTANT SAFEGUARDS

DAMAGE REQUIRING SERVICE

19.

Unplug this unit from the wall outlet and refer servicing to qualified service personnel under the following conditions:

When the power-supply cord or plug is damaged.

If liquid has been spilled, or objects have fallen into the unit.

If the unit has been exposed to rain or water.

If the unit does not operate normally by following the operating instructions. Adjust only those controls that are covered by the operating instructions, as an improper adjustment of other controls may result in damage and will often require extensive work by a qualified technician to restore the unit to its normal operation.

If the unit has been dropped or the cabinet has been damaged.

When the unit exhibits a distinct change in performance, this indicates a need for service.

REPLACEMENT PARTS

20.

When replacement parts are required, be sure the service technician uses replacement parts specified by the manufacturer or those that have the same characteristics as the original parts. Unauthorized substitutions may result in fire, electric shock or other hazards.

SAFETY CHECK

21.

Upon completion of any service or repairs to this unit, ask the service technician to perform safety checks to determine that the unit is in proper operating condition.

WALL OR CEILING MOUNTING

22.

The product should be mounted to a wall or ceiling only as recommended by the manufacturer.

HEAT

23.

The product should be situated away from heat sources such as radiators, heat registers, stoves, or other products (including amplifiers) that produce heat.

DISC TRAY

24.

Keep your fingers well clear of the disc tray as it is closing. It may cause serious personal injury.

CONNECTING

25.

When you connect the product to other equipment, turn off the power and unplug all of the equipment from the wall outlet. Failure to do so may cause an electric shock and serious personal injury. Read the owner's manual of the other equipment carefully and follow the instructions when making any connections.

SOUND VOLUME

26.

Reduce the volume to the minimum level before you turn on the product. Otherwise, sudden high volume sound may cause hearing or speaker damage.

SOUND DISTORTION

27.

Do not allow the product output distorted sound for a longtime. It may cause speaker overheating and fire.

HEADPHONES

28.

When you use the headphones, keep the volume at a moderate level. If you use the headphones continuously with high volume sound, it may cause hearing damage.

LEASER BEAM

29.

Do not look into the opening of the disc tray or ventilation opening of the product to see the source of the laser beam. It may cause sight damage.

DISC

30.

Do not use a cracked, deformed, or repaired disc. These discs are easily broken and may cause serious personal injury and product malfunction.

NOTE TO CATV SYSTEM INSTALLER

31.

This reminder is provided to call the CATV system installer’s attention to Article 820-40 of the NEC that provides guidelines for proper grounding and, in particular, specifies that the cable ground shall be connected to the grounding system of the building, as close to the point of cable entry as practical.

(CONTINUED)

EXAMPLE OF ANTENNA GROUNDING AS PER THE NATIONAL ELECTRICAL CODE

ELECTRIC SERVICE

NEC-NATIONAL ELECTRICAL

S2898A

GROUND CLAMP

EQUIPMENT

CODE

ANTENNA LEAD IN WIRE

ANTENNA DISCHARGE UNIT (NEC SECTION 810-20)

GROUNDING CONDUCTORS (NEC SECTION 810-21)

GROUND CLAMPS

POWER SERVICE GROUNDING ELECTRODE SYSTEM (NEC ART 250, PART H)

No. 52014 7

AV-20FD23

SPECIFIC SERVICE INSTRUCTIONS

DISASSEMBLY INSTRUCTIONS

1. REMOVAL OF MECHANICAL PARTS AND P.C. BOARDS

1-1: BACK CABINET (Refer to Fig. 1-1)

Remove the 7 screws 1.

Remove the screw 2 which are used for holding the Back Cabinet.

Remove the AC cord from the AC cord hook 3.

Remove the Back Cabinet in the direction of arrow.

Front Cabinet

1-2: CRT PCB (Refer to Fig. 1-2)

CAUTION: BEFORE REMOVING THE ANODE CAP,

DISCHARGE ELECTRICITY BECAUSE IT CONTAINS HIGH VOLTAGE. BEFORE ATTEMPTING TO REMOVE OR REPAIR ANY PCB, UNPLUG THE POWER CORD FROM THE AC SOURCE.

Remove the Anode Cap. (Refer to REMOVAL OF ANODE CAP)

Disconnect the following connector: (CP805).

Remove the CRT PCB in the direction of arrow.

Front Cabinet

Back Cabinet

CP805

Fig. 1-1

CRT PCB

1-3: POWER PCB/DVD BLOCK (Refer to Fig. 1-3)

Remove the 2 screws 1.

Disconnect the following connectors: (CP104, CP301, CP302, CP401 and CP3800).

Remove the POWER PCB/DVD Block in the direction of arrow.

CP3800

Front Cabinet

CP301

CP104

CP302

Power PCB/DVD Block

Fig. 1-3

1-4: POWER PCB (Refer to Fig. 1-4)

Remove the 11 screws 1.

Remove the Top Shield in the direction of arrow (A).

Disconnect the following connectors: (CP3802 and CP3803).

Remove the screw 2.

Remove the PCB Cover Ass'y in the direction of arrow (B).

Remove the screw 3.

Remove the Power PCB in the direction of arrow (C).

Power PCB

CP3803

PCB Cover Ass'y

(A)

CP3802

(C)

(B)

CP401

Fig. 1-2

8 No. 52014

Fig. 1-4

DISASSEMBLY INSTRUCTIONS

1-5: AV PCB/DVD PCB/DECK CD (Refer to Fig. 1-5)

Make the short circuit on the position as shown Fig. 1-5 using a soldering. If you remove the Deck CD with no soldering, the Laser may be damaged.

Disconnect the following connectors: (CP8001, CP8002 and CP8005).

Remove the 4 screws 1.

Remove the Deck Angle in the direction of arrow (A).

Disconnect the following connectors: (CP2301, CP2302 and CP2601).

Remove the 4 screws 2.

Remove the Deck CD in the direction of arrow (B).

Remove the 4 screws 3.

Remove the DVD PCB in the direction of arrow (C).

10.

Remove the 3 screws 4.

11.

Remove the AV PCB in the direction of arrow (D).

Pick Up PCB

Deck CD

AV-20FD23

DVD PCB

AV PCB

CP8002

(B)

(C)

(A)

(D)

Make the sort circuit using a soldering.

CP2601

CP2301

CP2302

CP8002

Deck Angle

CP8005

Bottom Plate

Fig. 1-5

NOTE

When the installation of the Deck CD, remove all the soldering on the short circuit position after the connection of Pick Up PCB and DVD PCB connector.

No. 52014 9

AV-20FD23

DISASSEMBLY INSTRUCTIONS

2. REMOVAL OF ANODE CAP

Read the following NOTED items before starting work.

After turning the power off there might still be a potential voltage that is very dangerous. When removing the Anode Cap, make sure to discharge the Anode Cap's potential voltage. Do not use pliers to loosen or tighten the Anode Cap

terminal, this may cause the spring to be damaged.

REMOVAL

1. Follow the steps as follows to discharge the Anode Cap.

(Refer to Fig. 2-1.)

Connect one end of an Alligator Clip to the metal part of a flat-blade screwdriver and the other end to ground. While holding the plastic part of the insulated Screwdriver, touch the support of the Anode with the tip of the Screwdriver. A cracking noise will be heard as the voltage is discharged.

GND on the CRT

3. After one side is removed, pull in the opposite direction to remove the other.

NOTE

Take care not to damage the Rubber Cap.

INSTALLATION

1. Clean the spot where the cap was located with a small amount of alcohol. (Refer to Fig. 2-3.)

NOTE

Confirm that there is no dirt, dust, etc. at the spot where the cap was located.

Location of Anode Cap

Fig. 2-3

Screwdriver

Alligator Clip

GND on the CRT

Flip up the sides of the Rubber Cap in the direction of the

2. arrow and remove one side of the support.

(Refer to Fig. 2-2.)

Rubber Cap

Support

CRT

Fig. 2-1

2.3.Arrange the wire of the Anode Cap and make sure the wire is not twisted. Turn over the Rubber Cap. (Refer to Fig. 2-4.)

Fig. 2-4

4. Insert one end of the Anode Support into the anode button, then the other as shown in Fig. 2-5.

CRT

Support

10 No. 52014

Fig. 2-2

Support

CRT

5.6.Confirm that the Support is securely connected. Put on the Rubber Cap without moving any parts.

Fig. 2-5

+ 23 hidden pages

JVC AV-20FD23 Service Manual

CONTENTS

SPECIFICATIONS

SAFETY PRECAUTIONS

IMPORTANT SAFEGUARDS

SPECIFIC SERVICE INSTRUCTIONS