LG Electronics TL-AT130M No Key display, OSD Circuit, No OSD display, No F.OSD display

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SECTION3 ELECTRICAL

ELECTRICAL TROUBLESHOOTING GUIDE

(3) No Key display

No Key display

YES

	Is there 5.2VA at IC501			NO
	Is there 5.2VA at IC501
	Pin79, 80, 81?

	YES			NO
	YES

	As pressing the byttons doeseach
	As pressing the byttons doeseach
	function work properly?
	function work properly?

Check power circuit

Replace bad switches

6. OSD CIRCUIT

(1) No OSD display.

No OSD display.

YES

Is there 5.3V IC501 Pin 51?		NO
Is there 5.3V IC501 Pin 51?

YES

NO

Does oscillation appear at the

IC501 PIns 37, 38?

YESNO

Does oscillation appear at the

IC501 Pins 40, 41?

YES

NO

Does Video signal appear at the

IC501 Pin 47?

YES

Replace IC501.

Check 5.3V Line of power circuity.

Replace X502.

Check peripheral circuit and replace X501

Check the signal between IC501 Pin47 and V.out Jack.

(2) No F.OSD display.

No F.OSD display.

YES

Refer to “(5) No OSD picture”		NO
Refer to “(5) No OSD picture”

YES

NO

Does video signal appear at

IC501 Pin 50?

YES

Replace IC501

Check power Vcc 9V

Check the signal between IC301 Pin 29 and IC501 Pin 49.

3-12

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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 When the drum moter stop Video is unstable in PB modePB mode 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 PB Mode No sound in EE Mode No sound in PB Mode No sound in EE Mode Audio CircuitNo sound in REC Mode No sound in REC ModeNo cassette tape loading SYSTEM/KEY Circuit Auto StopAuto Stop No OSD display No Key displayOSD Circuit 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-2-4Bracket Assembly L/D Motor Fig. A-2-4 Gear Assembly Rack F/L Fig. A-2-5Holder Assembly CST Fig.A-2-2 Arm Assembly F/L Fig. A-2-6Base Assembly A/C Head Arm AssemblyCleaner Head F/E Fig. A-3-2Arm Assembly Tension Fig. A-4-3 Brake Assembly T Fig. A-4-1Brake Assembly RS Fig. A-4-2 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-6-3Lever Spring Fig. A-7-6 Gear Sector Fig. A-7-3Lever Tension Fig. A-7-5 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 Tension Fig. A-9-2 Base Loading Fig. A-9-1 Arm Assembly Idler Fig. A-9-3Arm Assembly Idler Base Tension Base LoadingDeck Mechanism Adjustment Mechanism Alignment Position Check Fig. C-1Mechanism Condition Checking TorqueTest Equipment/ Fixture Test Conditions Torque Gauge 600g.cm ATG Cassette Torque Meter SRK-VHT-303Guide Roller Height Adjustment Head Assembly Audio/Control A/C Head AdjustmentAdjustment Procedure/Diagrams Head BaseAdjustment Procedure Adjustment Diagram Value AdjustmentPrecise Adjustment Azimuth adjustment 1KHZ 7KHZAdjustment after Replacing Drum Assembly Video Heads Check the Tape Travel after Reassembling Deck AssemblyCheck before starting repairs Maintenance Procedure Required MaintenanceScheduled Maintenance 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 LOCA.NO Description Specification Remarks Description SpecificationAssembly Section Remarks ScrewBuzzer LOCA.NO Description Specification Remark BATTERY,LITHIUMElectrecal section CapacitorLOCA.NO Description Specification Remark NP0 TS Coil DiodeFuse DigitronFilter HolderR121 0RD1800F608 R3G6 0RD1800F608 R553 0RD2200F608 R610 0RD2701F608 Switch LOCA.NO Description SpecificationRemote Controller Receiver Remark RESISTOR,DRAWINGTAL TransformerVaristor Zener Diode