LG Electronics TL-AT130M service manual Adjustment after Replacing Drum Assembly Video Heads

Page 55

DECK MECHANISM ADJUSTMENT

7. Adjustment after Replacing Drum Assembly (Video Heads)

Purpose: To correct for shift in the Roller Guide and X value after replacing the Drum.

Test Equipment/ Fixture

Connection Point

Test Conditions

Adjustment Points

(Mechanism Condition)

• Oscilloscope

• CH-1: PB RF Envelope

• Play the Blank Tape

• Guide Roller Precise

• Alignment Tapes

• CH-2: NTSC: SW 30Hz

• Play an Alignment Tape

Adjustment

• Blank Tape

PAL: SW 25Hz

 

• Switching Point

• Post Height Adjusting Driver

• Head Switching Output

 

• Tracking Preset

• Screw Driver(+) Type 5mm

Test Point

 

• X-Value

•RF Envelope Output Test Point

Checking/Adjustment Procedure

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Connection Diagram

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OSCILLOSCOPE

Play a blank tape and check for tape curling or creasing around

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the Roller Guide. If there is a problem then follow the procedure

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RF ENVELOPE OUTPUT TEST POINT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4. "Guide Roller Height" and 5. "Audio Control(A/C) Head

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CH1 CH2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Adjustment".

 

HEAD SWITCHING OUTPUT TEST

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

POINT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Waveform

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V1/V MAX E 0.7

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V1

 

 

 

 

V

 

 

 

 

 

 

V2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V2/V MAX E 0.8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RF ENVELOPE OUTPUT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fig. C-7

8. Check the Tape Travel after Reassembling Deck Assembly.

8-1. Checking Audio and RF Locking Time during playback and after CUE or REV (FF/REW)

Test Equipment/ Fixture

Specification

Test Equipment

Test Conditions

Connection Points

(Mechanism Condition)

 

 

Connection Points

• Oscilloscope

• RF Locking Time: Less than 5

• CH-1: PB RF Envelope

• Play an Alignment Tape

• Alignment Tapes(with 6H

sec.

• CH-2: Audio Output

(with 6H 3kHz Color Bar

3KHz Color Bar Signal)

• Audio Locking Time:Less than

• RF Envelope Output Point

Signal)

• Stop Watch

10sec

• Audio Output Jack

 

 

 

 

 

Checking Procedure

NOTES:

Play an Alignment Tape then change the operating mode to

1)

CUE is the forward search mode

CUE or REV and confirm if the unit meets the above listed

2)

REV is the backward search mode

specifications.

3)

Refer to the Play mede

8-2. Checking for tape curling or jamming

Test Equipment/ Fixture

Specification

Test ConditionsVCR(VCP)(MechanismState Condition)

 

 

 

• T-160 Tape

• Be sure there is no tape jamming or curling at

• Run the CUE, REV, Play mode at the

• T-120 Tape

the begining, middle or end of the tape.

beginning and the end of the tape.

 

 

 

Checking Procedure

1) Confirm that the tape runs smoothly around the roller

2) Confirm that the tape passes over the A/C Head

guides, Drum and A/C Head Assemblies while abruptly

Assembly as indicated by proper audio reproduction and

changing operating modes from Play to CUE or REV.

proper tape counter performance.

This is to be checked at the begining, middle and end

 

sections of the tape.

 

4-18

Page 54 Page 56
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Page 54 Page 56
Contents KEY Table of Contents Summary Rear FrontVCR Function Indication Indicator PanelIN/OUT Description Terminal Signal LevelsSummary Critical Parts Replacing Time Table Cabinet & Main Frame Exploded Views Cabinet and Main Frame Section Cabinet & Main Frame Section Parts listPacking & Accessory Section Packing Accessory Section Parts listConnection chart of PG adjustment PG AdjustmentNo 24 Power CircuitSMPS No 5.3 aNo 5.2 a to AVCP, Bias Servo Circuit Video is unstable in PB modePB mode When the drum moter stopCapstan motor stops When the capstan motor stopsNo Video in EE Mode No Video in EE ModeC Circuit Pin 16, 40, 55, 58, 87? Clean the Drum Check the System Circuit IC501 PinIs 5V applied to the IC301 Pin 16, 40, 55, 58, 87? Is the EE signal normal?Audio Circuit No sound in EE Mode No sound in PB ModeNo sound in EE Mode No sound in PB ModeNo sound in REC Mode No sound in REC ModeNo cassette tape loading SYSTEM/KEY Circuit Auto StopAuto Stop No F.OSD display No Key displayOSD Circuit No OSD displayElectrical Block & Circuit Diagrams Power Block Diagram Power Clrcuit Diagram Audio Block Diagram C Block Diagram V Circuit Diagram Electrical Block & Circuit Diagrams System Block Diagram Electrical Block & Circuit Diagrams System Clrcuit Diagram Jack Clrcuit Diagram KEY-BOARDCLRCUIT Diagram Electrical Printed Circuit Diagrams Jack P.C.BOARD KEY 1 P.C.BOARD KEY 2 P.C.BOARDMechanism Part Fixing Type Top View Bottom ViewDrum Motor Drum Assembly Fig. A-1-1Fig. A-2-4 Plate Top Fig. A-2-1Arm Assembly F/L Fig. A-2-6 Gear Assembly Rack F/L Fig. A-2-5Holder Assembly CST Fig.A-2-2 Bracket Assembly L/D Motor Fig. A-2-4Head F/E Fig. A-3-2 Arm AssemblyCleaner Base Assembly A/C HeadReel S / Reel T Fig. A-4-4 Brake Assembly T Fig. A-4-1Brake Assembly RS Fig. A-4-2 Arm Assembly Tension Fig. A-4-3Opener Lid Fig. A-5-2 Arm Assembly Pinch Fig. A-5-3Lever T/up Fig. A-5-4 Arm T/up Fig. A-5-5 Lever F/R Fig. A-6-3 Brake Assembly CapstanJust lift the Plate Slider up Gear Sector Fig. A-7-3Lever Tension Fig. A-7-5 Lever Spring Fig. A-7-6Base Assembly P2 Fig. A-8-3/ Base Assembly P3 Fig. A-8-4 Gear Assembly P2 Fig. A-8-1/ Gear Assembly P3 Fig. A-8-2Base Tension Base Loading Base Loading Fig. A-9-1 Arm Assembly Idler Fig. A-9-3Arm Assembly Idler Base Tension Fig. A-9-2Deck Mechanism Adjustment Fig. C-1 Mechanism Alignment Position CheckTorque Gauge 600g.cm ATG Cassette Torque Meter SRK-VHT-303 Checking TorqueTest Equipment/ Fixture Test Conditions Mechanism ConditionGuide Roller Height Adjustment Head Base Audio/Control A/C Head AdjustmentAdjustment Procedure/Diagrams Head Assembly1KHZ 7KHZ Value AdjustmentPrecise Adjustment Azimuth adjustment Adjustment Procedure Adjustment DiagramCheck the Tape Travel after Reassembling Deck Assembly Adjustment after Replacing Drum Assembly Video HeadsCheck before starting repairs Cleaning Required MaintenanceScheduled Maintenance Maintenance ProcedureChassis Bottom Chassis Top GreasingGear Sector Gear Cam Base Loading Gear Drive Gear AY, P2 & P3 Lever, F/R, Base, TensionBase, Tension Mechanism Troubleshooting Guide Auto Stop PLAY/CUE/REV Is the Belt ok? NonoFront Loading Mechanism Cassette does not load Exploded Views Moving Mechanism A11 RUN Date NSP Not Service PartParts Section Screw Description SpecificationAssembly Section Remarks LOCA.NO Description Specification RemarksCapacitor LOCA.NO Description Specification Remark BATTERY,LITHIUMElectrecal section BuzzerLOCA.NO Description Specification Remark NP0 TS Diode CoilHolder DigitronFilter FuseR121 0RD1800F608 R3G6 0RD1800F608 R553 0RD2200F608 R610 0RD2701F608 RESISTOR,DRAWING LOCA.NO Description SpecificationRemote Controller Receiver Remark SwitchZener Diode TransformerVaristor TAL
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