JVC AV-20NMG3B, AV-20N3/D, AV-20NMG3/-A Specific Service Instructions, Disassembly Procedure

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AV-20N3

AV-20NMG3

AV-20NMG3B

SPECIFIC SERVICE INSTRUCTIONS

DISASSEMBLY PROCEDURE

REMOVING THE REAR COVER

1.Unplug the power plug.

2.As shown in figure, remove the 6 screws marked ! and a screw marked ".

3.Withdraw the rear cover toward you.

REMOVING THE MAIN PW BOARD

"After removing the rear cover.

1.Slightly raise the both sides of the MAIN PW BOARD by hand.

2.Withdraw the MAIN PW BOARD backward.

(If necessary, take off the wire clamp, connectors etc.)

REMOVING THE SPEAKER

"After removing the rear cover.

1.As shown in figure, remove the 2 screws marked #.

2.Follow the same steps when removing the other hand speaker.

CHECKING THE MAIN PW BOARD

1.To check the back side of the PW Board.

1)Pull out the MAIN PW Board. (Refer to REMOVING THE MAIN PW Board)

2)Erect the PW Board vertically so that you can easily check the back side of the PW Board.

[CAUTION]

"When erecting the PW Board, be careful so that there will be no contacting with other PW Board.

"Before turning on power, make sure that the CRT earth wire and other connector are properly connected.

WIRE CLAMPING AND CABLE TYING

1.Be sure to clamp the wire.

2.Never remove the cable tie used for tying the wires together. Should it be inadvertently removed, be sure to tie the wires with a new cable tie.

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No. 52025

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Contents Contents Specifications EntsAV-20N3 AV-20NMG3Safety Precautions Features Memory SCL 2/SDA2Micro Computer VIDEO/CHROMA Decorder SCL 1/SDA1Functions Front Panel Rear TerminalRemote Control Unit Model Name Main Difference ListPart Name Specific Service Instructions Disassembly ProcedureSpeaker KEY Assignment of Remote Control Unit Service MenuSystem CONSTANT-Ⅰ System CONSTANT-ⅡSetting of System Constant SET Setting item Setting contentsUser Setting Values Setting item Setting valueInitial Setting Value of Service Menu PAL Secam PresetSound System Do Not Adjust Setting item Locations of Front Panel Buttons and LAM PS Replacement of IC301 if V/C DecoderProcedures Service Adjustments Before Starting Service AdjustmentAdjustment Items Measuring Instrument and FixturesBasic Operation of Service Menu KEY Assignment of Remote Control Unit Service MenuMethod of setting C, 3.DEF and 4.VSM PresetSetup Tour Should be OFFService Menu Flow Chart Adjustment Locations Solder SideTOP UpperfocusAdjustments B1 Power SupplyFocus Adjustment If Circuit AdjustmentDelay Point PointAGC AGC Take Over OtherVideo / Chroma Circuit Adjustment Method of adjustment without measuring instrument SUB BrightAd justment Remote SUBColour Ⅱ Socket TintCRT BL Adjust Ad justment part Description RemoteSecam Control unit BL ACKDeflection Circuit Adjustment PositionVSM Preset Setting VER. ScurveScurve TOP# P/C Magnets Purity / Convergence AdjustmentPurity Adjustment Static Convergence Adjustment Dynamic Convergence AdjustmentSoldering Iron Replacement of Chip ComponentReplacement Steps AV-20N3 AV-20NMG3 AV-20NMG3B