LG Electronics TL-AT130M service manual Guide Roller Height Adjustment

Page 52

DECK MECHANISM ADJUSTMENT

4.Guide Roller Height Adjustment

Purpose: To regulate the height of the tape so that the bottom of the tape runs along the tape guide line on the Lower Drum.

4-1. Preliminary Adjustment

Test Equipment/ Fixture

Test Conditions (Mechanism Condition)

Adjustment Point

 

 

 

• Post Height Adjusting Driver

• Play or Review Mode

• Guide Roller Height Adjustment

 

 

screws on the Supply and Take-Up

 

 

Guide Rollers.

 

 

 

Adjustment Procedure

1)Confirm if the tape runs along the tape guide line of the Lower Drum.

2)If the tape runs the bottom of the guide line, turn the Guide Roller Height Adjustment Screw to clockwise direction.

3)If it runs the top, turn to counterclockwise direction.

4)Adjust the height of the Guide Roller to be guided to the guide line of the Lower Drum from the starting and end- ing point of the Drum.

ADJUSTMENT DIAGRAM Guide Roller Height

Adjustment screw

Upper Flange

Guide Roller

Retaining Screw

Fig. C-4-1

4-2. Precise Adjustment

 

 

 

Test Equipment/Fixture

Test Equipment Connection Points

Test Conditions VCR(VCP) State

Adjustment Point

• Oscilloscope

• CH-1:PB RF Envelope

• Play an Alignment Tape

• Guide Roller Height

• Alignment Tape

• CH-2:NTSC: SW 30Hz

 

Adjustment Screws

• Post Height Adjusting

PAL: SW 25Hz

Waveform Diagrams

 

Driver

• Head Switching Output

 

 

Point

P2 POST

 

 

• RF Envelope Output

 

 

ADJUSTMENT

 

 

Point

 

 

 

 

Adjustment Procedure

1)Play an Alignment Tape after connecting the probe of the Oscilloscope to the RF Envelope Output Test Point and

Head Switching Output Test Point.

 

Turn the Roller Guide Height

2) Tracking Control(in PB Mode) : Center Position(When

P3 POST

this adjustment is performed after the Drum Assembly

Adjustment Screw slightly

ADJUSTMENT

to flatten the waveform.

has been replaced, set the Tracking Control so that the

 

 

Fig. C-4-2

RF Output is Maximum).

 

3)Height Adjustment Screw : Flatten the RF waveform. (Fig. C-4-2)

4)Turn(Move) the Tracking Control(in PB Mode) clockwise

and counterclockwise.(Fig. C-4-3)

 

Tracking Control at center

Turn(Move) the Tracking

5) Check that any drop of RF Output is uniform at the start

 

Control to both directions

 

 

 

and end of the waveform.

 

Fig. C-4-3

NOTE

 

 

 

 

 

 

 

 

 

 

 

Connection Diagram

 

 

 

 

 

 

 

If the adjustment is excessive or insufficient the tape will

 

 

 

 

 

 

OSCILLOSCOPE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

jam or fold.

 

 

 

 

 

 

 

 

 

 

 

 

RF ENVELOPE OUTPUT TEST POINT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

HEAD SWITCHING OUTPUT TEST

 

 

 

 

 

 

 

 

POINT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4-15

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Page 51 Page 53
Contents KEY Table of Contents Summary Front RearIndicator Panel VCR Function IndicationTerminal Signal Levels IN/OUT DescriptionSummary Critical Parts Replacing Time Table Cabinet & Main Frame Exploded Views Cabinet & Main Frame Section Parts list Cabinet and Main Frame SectionPacking Accessory Section Parts list Packing & Accessory SectionPG Adjustment Connection chart of PG adjustmentPower CircuitSMPS No 5.3 a No 24No 5.2 a to AVCP, Bias Video is unstable in PB mode PB modeWhen the drum moter stop Servo CircuitWhen the capstan motor stops Capstan motor stopsNo Video in EE Mode No Video in EE ModeC Circuit Clean the Drum Check the System Circuit IC501 Pin Pin 16, 40, 55, 58, 87?Is the EE signal normal? Is 5V applied to the IC301 Pin 16, 40, 55, 58, 87?No sound in EE Mode No sound in PB Mode No sound in EE ModeNo sound in PB Mode Audio CircuitNo sound in REC Mode No sound in REC ModeNo cassette tape loading SYSTEM/KEY Circuit Auto StopAuto Stop No Key display OSD CircuitNo OSD display No F.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 KEY 1 P.C.BOARD KEY 2 P.C.BOARD Jack P.C.BOARDMechanism Top View Bottom View Part Fixing TypeDrum Assembly Fig. A-1-1 Drum MotorPlate Top Fig. A-2-1 Fig. A-2-4Gear Assembly Rack F/L Fig. A-2-5 Holder Assembly CST Fig.A-2-2Bracket Assembly L/D Motor Fig. A-2-4 Arm Assembly F/L Fig. A-2-6Arm Assembly CleanerBase Assembly A/C Head Head F/E Fig. A-3-2Brake Assembly T Fig. A-4-1 Brake Assembly RS Fig. A-4-2Arm Assembly Tension Fig. A-4-3 Reel S / Reel T Fig. A-4-4Opener 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 Brake Assembly Capstan Lever F/R Fig. A-6-3Gear Sector Fig. A-7-3 Lever Tension Fig. A-7-5Lever Spring Fig. A-7-6 Just lift the Plate Slider upGear Assembly P2 Fig. A-8-1/ Gear Assembly P3 Fig. A-8-2 Base Assembly P2 Fig. A-8-3/ Base Assembly P3 Fig. A-8-4Base Loading Fig. A-9-1 Arm Assembly Idler Fig. A-9-3 Arm Assembly IdlerBase Tension Fig. A-9-2 Base Tension Base Loading Deck Mechanism Adjustment Mechanism Alignment Position Check Fig. C-1Checking Torque Test Equipment/ Fixture Test ConditionsMechanism Condition Torque Gauge 600g.cm ATG Cassette Torque Meter SRK-VHT-303Guide Roller Height Adjustment Audio/Control A/C Head Adjustment Adjustment Procedure/DiagramsHead Assembly Head BaseValue Adjustment Precise Adjustment Azimuth adjustmentAdjustment Procedure Adjustment Diagram 1KHZ 7KHZAdjustment after Replacing Drum Assembly Video Heads Check the Tape Travel after Reassembling Deck AssemblyCheck before starting repairs Required Maintenance Scheduled MaintenanceMaintenance Procedure CleaningChassis 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 Nono Is the Belt ok?Front Loading Mechanism Cassette does not load Exploded Views Moving Mechanism A11 RUN Date NSP Not Service PartParts Section Description Specification Assembly Section RemarksLOCA.NO Description Specification Remarks ScrewLOCA.NO Description Specification Remark BATTERY,LITHIUM Electrecal sectionBuzzer CapacitorLOCA.NO Description Specification Remark NP0 TS Coil DiodeDigitron FilterFuse HolderR121 0RD1800F608 R3G6 0RD1800F608 R553 0RD2200F608 R610 0RD2701F608 LOCA.NO Description Specification Remote Controller Receiver RemarkSwitch RESISTOR,DRAWINGTransformer VaristorTAL Zener Diode
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