LG Electronics TL-AT130M service manual SYSTEM/KEY Circuit Auto Stop, No cassette tape loading

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SECTION3 ELECTRICAL

ELECTRICAL TROUBLESHOOTING GUIDE

5.SYSTEM/KEY CIRCUIT

(1) AUTO STOP

Auto Stop

YES

Does SW waveform appear at IC501 NO

pin23?

YES

Check Drum motor signal

Does T/up reel pulse appear

NO

Does T/up reel pulse appear

NO

Is there 5.3V at RS501?

at IC501 Pin27?

at Q514 Base terminal?

YES

YES

YES

NO

Replace T/up reel sensor of deck

Check DP06, LP03

Replace IC501

Check power circuit

(2) No cassette tape loading

No cassette tape loading

YES

Is there REG. 12V at PMCQ1

Pin8?

YES

Does 'H' signal appear at IC501

Pin62 while inserting CST?

YES

NO

Check power circuit L104.

NO

Is there 5.3V at IC501 Pin73?

YES			NO

Check CST SW and peripheral circuit

Check power circuit

Check D106, L103.

NO

Check Deck mechanism

Check IC501 Pin7, 8, 9, 10

*Caution : Auto stop can occur because Grease or Oil is dried up

3-11

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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 PB mode Video is unstable in PB modeWhen the drum moter stop Servo CircuitCapstan 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?No sound in EE Mode No sound in EE Mode No sound in PB ModeNo sound in PB Mode Audio CircuitNo sound in REC Mode No sound in REC ModeSYSTEM/KEY Circuit Auto Stop No cassette tape loadingAuto Stop OSD Circuit No Key displayNo 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 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-2-1Holder Assembly CST Fig.A-2-2 Gear Assembly Rack F/L Fig. A-2-5Bracket Assembly L/D Motor Fig. A-2-4 Arm Assembly F/L Fig. A-2-6Cleaner Arm AssemblyBase Assembly A/C Head Head F/E Fig. A-3-2Brake Assembly RS Fig. A-4-2 Brake Assembly T Fig. A-4-1Arm Assembly Tension Fig. A-4-3 Reel S / Reel T Fig. A-4-4Arm Assembly Pinch Fig. A-5-3 Opener Lid Fig. A-5-2Lever T/up Fig. A-5-4 Arm T/up Fig. A-5-5 Lever F/R Fig. A-6-3 Brake Assembly CapstanLever Tension Fig. A-7-5 Gear Sector Fig. A-7-3Lever Spring Fig. A-7-6 Just lift the Plate Slider upBase 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-8-2Arm Assembly Idler Base Loading Fig. A-9-1 Arm Assembly Idler Fig. A-9-3Base Tension Fig. A-9-2 Base Tension Base LoadingDeck Mechanism Adjustment Fig. C-1 Mechanism Alignment Position CheckTest Equipment/ Fixture Test Conditions Checking TorqueMechanism Condition Torque Gauge 600g.cm ATG Cassette Torque Meter SRK-VHT-303Guide Roller Height Adjustment Adjustment Procedure/Diagrams Audio/Control A/C Head AdjustmentHead Assembly Head BasePrecise Adjustment Azimuth adjustment Value AdjustmentAdjustment Procedure Adjustment Diagram 1KHZ 7KHZCheck the Tape Travel after Reassembling Deck Assembly Adjustment after Replacing Drum Assembly Video HeadsCheck before starting repairs Scheduled Maintenance Required MaintenanceMaintenance Procedure CleaningGreasing Chassis Bottom Chassis TopGear Sector Gear Cam Base Loading Gear Drive Lever, F/R, Base, Tension Gear AY, P2 & P3Base, 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 NSP Not Service Part RUN DateParts Section Assembly Section Remarks Description SpecificationLOCA.NO Description Specification Remarks ScrewElectrecal section LOCA.NO Description Specification Remark BATTERY,LITHIUMBuzzer CapacitorLOCA.NO Description Specification Remark NP0 TS Diode CoilFilter DigitronFuse HolderR121 0RD1800F608 R3G6 0RD1800F608 R553 0RD2200F608 R610 0RD2701F608 Remote Controller Receiver Remark LOCA.NO Description SpecificationSwitch RESISTOR,DRAWINGVaristor TransformerTAL Zener Diode