JVC RX-8020VBK Service Manual

SERVICE MANUAL

AUDIO/VIDEO CONTROL RECEIVER

RX-8020VBK

Area suffix

RX-8020VBK

A/V CONTROL RECEIVER

CATV/DBS VCR1 TV AUDIO

DVD MULTIDVD

CDR

TV/DBS VIDEO PHONO

TAPE/MD

VCR1 VCR 2

SURR/DSP

ANALOG/DIGITAL

DSP

SURROUND

OFF

ANALOG

BASS

DIRECT

BOOST FRONT•L

231

SOUND

TEST CENTER SUBWFR

564

ENTER

SURR•L SURR•R

DIMMER

7/P

SBACK•L SBACK•R

DIGITAL EQ

MUTING

RETURN FM MODE 100 CATV/DBS CONTROL

CH/

LEVEL

TV VOL

TV/VIDEO

TEXT

PLAY

DISPLAY

REC

/REW

PAUSE

SET

DOWN – TUNING – UP

SLEEP

CONTROL

STOP

RM-SRX8020J

REMOTE CONTROL

FM/AM

USB

INPUT

FRONT•R

+10

VOLUME

EXIT

FF/

SPEAKERS ON/OFF

SUBWOOFER OUT ON/OFF

PHONES

STANDBY

STANDBY/ON

FM/AM TUNING FM/AM PRESET FM MODE

SURROUND

Contents

USB AUDIO

PUSH OPEN

DSP

S-VIDEO VIDEO

MEMORY

SURROUND/DSP

OFF

VIDEO

L—AUDIO—R

INPUT

ANALOG/DIGITAL

INPUT ATT

RX-8020V

AUDIO/VIDEO CONTROL RECEIVER

SOURCE NAME

TV SOUND/DBSVIDEOVCR 2VCR 1DVDDVD MULTI

SOUCE NAME

FM/AMUSB AUDIOTAPE/MDCDRCDPHONO

DIGITAL

EFFECT SETTING

CONTROL

DOWN UP

UJ ---------- U.S.Military

MASTER VOLUME

LEVEL ADJUST

ANALOG DIRECT

BASS BOOST

Safety precautions --------------------------------------------------------1-2 Disassembly method -----------------------------------------------------1-3 Adjustment method -------------------------------------------------------1-9 Self-diagnose function-----------------------------------------------------1-10 Description of major ICs -------------------------------------------------1-12~31

No.21161 Oct. 2002

RX-8020VBK

1. This design of this product contains special hardware and many circuits and components specially for safety purposes. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Services should be performed by qualified personnel only.

2. Alterations of the design or circuitry of the product should not be made. Any design alterations of the product should not be made. Any design alterations or additions will void the manufacturer`s warranty and will further relieve the manufacture of responsibility for personal injury or property damage resulting therefrom.

3. Many electrical and mechanical parts in the products have special safety-related characteristics. These

characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in the Parts List of Service Manual. Electrical components having such features are identified by shading on the schematics and by ( ) on the Parts List in the Service Manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement parts shown in the Parts List of Service Manual may create shock, fire, or other hazards.

4. The leads in the products are routed and dressed with ties, clamps, tubings, barriers and the like to be separated from live parts, high temperature parts, moving parts and/or sharp edges for the prevention of electric shock and fire hazard. When service is required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after re-assembling.

5. Leakage currnet check (Electrical shock hazard testing) After re-assembling the product, always perform an isolation check on the exposed metal parts of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock. Do not use a line isolation transformer during this check.

Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure the leakage current from each exposed metal parts of the cabinet, particularly any exposed metal part having a return path to the chassis, to a known good earth ground. Any leakage current must not exceed 0.5mA AC (r.m.s.).

Alternate check method Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000 ohms per volt or more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by a 0.15 F AC-type capacitor between an exposed metal part and a known good earth ground. Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to each exposed metal part, particularly any exposed metal part having a return path to the chassis, and meausre the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Voltage measured any must not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.).

0.15 F AC TYPE

1500 10W

Good earth ground

AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity)

Place this probe on each exposed metal part.

1. This equipment has been designed and manufactured to meet international safety standards.

2. It is the legal responsibility of the repairer to ensure that these safety standards are maintained.

3. Repairs m ust be made in accordance with the relevant safety standards.

4. It is essential that safety critical components are replaced by approved parts.

5. If mains voltage selector is provided, check setting for local voltage.

Burrs formed during molding may be left over on some parts of the chassis. Therefore, pay attention to such burrs in the case of preforming repair of this system.

In regard with component parts appearing on the silk-screen pr inted side (parts side) of the PWB diagrams, the parts that are printed over with black such as the resistor ( ), diode ( ) and ICP ( ) or identified by the " " mark nearby are critical for safety.

(This regulation does not correspond to J and C version.)

1-2

RX-8020VBK

Disassembly method

Removing the top cover (See Fig.1)

Remove the four screws A attaching the top cover on both sides of the body.

Remove the three screws B on the back of the body.

Remove the top cover from behind in the direction of the arrow while pulling both sides outward.

Removing the front panel assembly

(See Fig.2 and 3)

Prior to performing the following procedure, remove the top cover.

Cut off the tie bands.

Disconnect the harness from the connector CN416 (on the video audio board), CN206 (on the video board) and CN244 (on the S video board) (see fig.8).

Disconnect the card wire from the connector CN400 on the audio board and CN402 on the power supply board.

Remove the three screws C fixing the upper surface of the front panel, and four screws D fixing the bottom.

Main

board

Audio board

CN400

Top cover

(both sides)

Fig.1

Front panel assembly

Power supply board

CN402

Tie band

Compu link board

CN393

Fig.2

Detach the front panel assembly toward the front.

Remove the screw X attaching the earth wire (see fig.

19).

Removing the compulink board (See Fig.2 and 4)

Prior to performing the following procedure, remove the top cover.

Disconnect the harness from the connector CN393 on the compu link board.

Remove the three screws E attaching the compu link board to the rear panel.

Removing the rear panel (See Fig.4)

Prior to performing the following procedure, remove the top cover.

Remove the power cord stopper from the rear panel by moving it in the direction of the arrow.

Front panel assembly

Fig.3

Cord stopper

FFF FE G

Remove the thirty seven screws E & F & G & H attaching the each board to the rear panel.

Remove the three screws I attaching the rear panel on the back of the body.

Rear panel

FIIHI

Fig.4

1-3

RX-8020VBK

Removing the DVD board (See Fig.5 and 6)

Prior to performing the following procedure, remove the top cover and rear panel.

Cut off the tie bands.

Disconnect the harness from the connector CN393 on the compu link board (see fig.2).

Disconnect the harness from the connector CN721, CN723 on the main board and CN722 on the Cch amp. board.

Remove the two fasteners fixing the small board to the audio input board and video board.

Draw out the DVD board upwards, disconnecting the connector CN501, CN243, CN205, CN381 and CN361 on the DVD board.

Removing the each board of the tuner, the audio input, the video audio, the video, the S video and the DSP (See Fig.7 to 10)

Main board

CN721 CN723

CN361 CN381 CN205

Small board

Fastener

Video audio board

Audio input board

Video board

CN722 (on the Cch amp. board)

Tie band

DVD board

CN501 CN243

Fig.5

DVD board

Fig.6

S Video board

DSP board

Prior to performing the following procedure, remove the top cover, rear panel and DVD board.

Remove the tuner board from the connector CN101 on the audio board.

Remove the audio input board from the connector CN301 on the audio board.

Disconnect the harness from the connector CN416 and remove the video audio board from the connector CN303 on the audio board.

Disconnect the harness from the connector CN206 and remove the video board from the connector CN201 on the audio board.

Disconnect the harness from the connector CN244 and remove the S video board from the connector CN241 on the audio board.

Remove the DSP board from the connector CN601 on the audio board.

Tuner board

Fig.7

CN244 (on the S video board)

1-4

CN206 (on the video board)

CN416 (on the video audio board)

Fig.8

RX-8020VBK

Audio board

CN101

CN301 CN303

CN201

Fig.9

Removing the speaker board (See Fig.11)

Prior to performing the following procedure, remove the top cover and rear panel.

Disconnect the harness from the connector CN931/

1. CN932 on the audio board.

Disconnect the harness from the connector CN813

2. and CN814 on the main board.

CN601 CN241

Main board

Connection between the audio board and each board

CN101 CN301 CN303 CN201 CN241 CN601

Tuner board (CN111) Audio input board (CN311) Vidoe audio board (CN313) Video board (CN200) S video board (CN240) DSP board (CN587)

Fig.10

Relay board

Power supply board

CN71 Tie band

CN814 CN813

CN931

/CN932

Power transformer

CN81

Removing the audio board (See Fig.11 and 12)

Prior to performing the following procedure, remove the top cover, rear panel, DVD board, tuner board, audio input board, video audio board, video board, S video board and DSP board.

Disconnect the harness and card wire from the

1. connector CN931 /CN932 and CN400 on the audio board.

Cut off the tie band, if needed.

2. Disconnect the connector CN71(on the power supply

3. board) and CN81(on the audio board) and remove the relay board.

Disconnect the harness from the connector CN831 on

4. the main board.

Remove the three screws J and screw K attaching the

5. audio board.

Audio board

CN831 CN400

Audio board

Speaker board

Fig.11

Fig.12

1-5

RX-8020VBK

Removing the main board (See Fig.13 to 15)

Prior to performing the following procedure, remove the top cover.

Remove the card wire and cut off the tie bands.

Disconnect the harness from the connector CN721, CN723, CN813, CN814, CN831 and CN881 on the main board.

Disconnect the harness from the connector CN722 on the Cch amp. board (see fig.5).

Disconnect the harness from the connector CN811 on the power trans1 board.

Remove the screw K, after removing the relay board if needed (see fig.11).

Remove the two screws L and the six screws M attaching the main board.

Remove the two screws N attaching the heat sink to the main board.

Disconnect the connector of each amp. board.

Card wire

Main board

CN831 CN814 CN813

CN723

CN721

Tie band

Fig.13

Heat sink

Main board (reverse side)

Fig.14

Tie band

CN811

Power trans1 board

CN722

CN881

Removing the each amp. board of Cch, Lch, Rch, RLch and RRch (See Fig.16)

Prior to performing the following procedure, remove the top cover and main board.

Remove the two screws O attaching the Cch amp. board and remove the Cch amp. board.

Remove the two screws P attaching the Lch amp. board and remove the Lch amp. board.

Remove the two screws Q attaching the Rch amp. board and remove the Rch amp. board.

Remove the two screws R attaching the RLch amp. board and remove the SLch amp. board.

Remove the two screws S attaching the RRch amp. board and remove the SRch amp. board.

Removing the Heat sink (See Fig.16)

Prior to performing the following procedure, remove the top cover, main board and each amp. board.

RLch amp. board

RRch amp. board

Main board

CN706

CN705

CN702

(RRch)

Heat sink

CN701

Fig.15

(Rch)

Rch amp. board

Lch amp. board

Cch amp. board

Heat sink

CN703

(Cch)

Remove the four screws T attaching the two

1. brackets to the heat sink and remove the two brackets.

1-6

Bracket

(RLch)

Fig.16

(Lch)

Bracket

Removing the power transformer (See Fig.17)

Prior to performing the following procedures, remove the top cover.

Disconnect the harness from the connector CN55 /CN56 and CN811 on the power trans1 board.

Unsolder the seven solder parts on the power trans2 board.

Remove the four screws U attaching the power transformer.

Removing the voltage selector board (See Fig.17)

Prior to performing the following procedure, remove the top cover.

Removed the two screws G attaching the voltage selector board to the rear panel (see fig.4).

Unsolder the six solder parts on the voltage selector board.

CN55/CN56

CN811

Solder part

RX-8020VBK

Power supply board

Power trans1 board

Power transformer

Power trans2 board

Voltage selector board

Removing the power/fuse board (See Fig.17)

Prior to performing the following procedure, remove the top cover.

Removed the two screws G attaching the voltage selector board to the rear panel (see fig.4).

Remove the screw H attaching the power/fuse board to the rear panel (see fig.4).

Remove the screw V attaching the power/fuse board.

Unsolder the eight solder parts on the power/fuse board.

Removing the power supply board

(See Fig.18)

Prior to performing the following procedure, remove the top cover and relay board.

Cut off the tie band if needed.

Disconnect the card wire from the connector CN402 on the power supply board.

Power cord

Solder part

(on the reverse side)

Headphone jack board

Power supply board

CN402

Solder part

(on the reverse side)

Fig.17

Under this board

Power/fuse board

Solder part

Headphone jack

Disconnect the harness from the connector CN55/CN56 on the power trans1 board (see fig.17).

Remove the three screws W attaching the power supply board and pull out the power supply board removing the hook.

Unsolder the three solder parts on the power supply board.

Solder part

(on the reverse side)

Hook

Fig.18

Tie band

1-7

RX-8020VBK

)

Removing the headphone jack board

(See Fig.18 and 19)

Prior to performing the following procedure, remove the top cover, front panel assembly and power supply board.

Disconnect the harness form the connector CN881 on the main board (see fig.13).

Remove the nut fixing the headphone jack.

Drawn out the headphone jack board in the direction of an inner side.

Removing the system control board, power switch board and switch board (See Fig.1 to 3)

Prior to performing the following procedure, remove the top cover and front panel assembly.

Bracket

Headphone

jack

Operation switch panel

Front panel

assembly

(inner side)

Earth wire

Nut

Fig.19

Nut

Pull out the volume knob on the front side of the front panel assembly and remove the nut attaching the system control board.

Remove the two screws A attaching the power switch board on the front panel assembly(inner side). And disconnect the harness from the connector CN430 on the power switch board.

Remove the two screws B attaching the switch board on the front panel assembly(inner side). And disconnect the harness form the connector CN432 on the switch board.

Remove the harness from the three hooks a.

Remove the eight screws C attaching the operation switch panel from the inner side of the front panel assembly.

Release the four joints on the front panel assembly (inner side) by pushing the joint tabs inward. Remove the operation switch panel toward the front.

Release the two hooks b attaching the system control board.

CN432

Volume knob

Switch board

Joint

CN412

Fig.1

Front panel assembly (inner side

Power switch board

Joint

System control board

Joint

Fig.2

Hook a

Joint

CN430

Disconnect the card wire from the connector CN410 and CN412 on the system control board.

1-8

Hook b

CN410

Adjustment method

Tuner section

1.Tuner range FM 87.5MHz~108.0MHz AM(MW) 531 kHz to 1 602 kHz (at 9 kHz intervals) 530 kHz to 1 600 kHz (at 10 kHz intervals)

Power amplifier section

Adjustment of idling current

Measurement location B2204-B2205(Lch) , B2213-2214(Rch) Adjustment part VR787(Lch) , VR788(Rch)

Attention This adjustment does not obtain a correct adjustment value immediately after the amplifier is used (state that an internal temperature has risen). Please adjust, after you turn off amplifier and internal temperature falls.

RX-8020VBK

1.Set the volume control to minimum during this adjustment.(No signal & No load)

2.Set the surround mode OFF.

2.Turn VR787 and VR788 fully counterclockwise to warm up before adjustment. If the heat sink is already warm from previous use the correct adjustment can not be made.

3.For L-ch,connect a DC voltmeter between B2204 and B2205 (Lch) And,connect it between B2213 and B2214(Rch).

4.30 minutes later after power on, adjust VR787 for L-ch, or VR788 for R-ch so that the DC voltmeter value has 1mV~10mV.

* It is not abnormal though the idling current might not become 0mA even if it is finished to turn variable resistance (VR787,VR788) in the direction of counterclockwise.

Heat sink

Rch amp. board

VR788 (Rch)

Lch amp. board

B2213, B2214

VR787 (Lch) B2204, B2205

1-9

RX-8020VBK

Self-diagnose function

1. Detection of abnormal power supply and voltage

When the power is turned ON, if an abnormality is detected during the signal input at the A/D port (IC901, pin 2-5, 7) for one second continuously, the status will become STANDBY mode immediately.

When the power is turned ON again, detection of abnormal power supply and voltage will not be carried out during the first 4 seconds.

Given below is a list of threshold values at the detection of abnormalities.

Pin 2 Micro-computer+5V Pin 3 Digital+5V Pin 4 Analog+5V Pin 5 +12V Pin 7 Tuner+9V

At abnormal state (Low voltage) Analog value 0 - 2.2V Analog value 0 - 2.2V Analog value 0 - 2.2V Analog value 0 - 2.2V Analog value 0 - 2.2V

At normal state

Analog value

2.2 - 2.8V Analog value

2.2 - 2.8V

At abnormal state (High voltage) Analog value

2.8 - 5.0V Analog value

2.8 - 5.0V

2. Initial setting on ship

To gain the initial setting on ship, put the power plug in the socket while pressing "DOWN" key and "UP" key together simultaneously, then turn the power ON.

3. Test mode

To enter the test mode, put the power plug in the socket while pressing "EFFECT" key and "UP" key together simultaneously, then turn the power ON.

Workings of test mode: All FLs are turned ON for 3 seconds. (the FLs, which are divided in two groups, are turned ON alternatively) A Faster volume UP/DOWN operation can be achieved with the remote controller.

When the power is turned OFF, the test mode will be released. The FL display returns to normal after the three seconds. Then the STANDBY LED is turned ON (flashing

ON and OFF for each one second) to show the present status being a test mode.

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+ 22 hidden pages