LG Electronics TL-AT130M service manual No 5.2 a to AVCP, Bias

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SECTION3 ELECTRICAL

ELECTRICAL TROUBLESHOOTING GUIDE

(4) No 5.2 A (TO AVCP, BIAS)

(5) No 10V

No 5.2V

Is D106 normal?

YES

Is Q153 normal?

YES

NO

NO

Replace D106.

Replace Q153.

No 10V

NO

Is D109 normal?

YES

Is Q170 normal?, Is there about			NO
13.5V at Q107 Base?
13.5V at Q107 Base?

YES

Replace D109

Check/ Replace

Q107, ZD103

Is there voltage (about 0V)	NO
at Q157 collector.
at Q157 collector.

YES

Check/

Replace Q156

Replace Q157.

Check/ Replace

D155, D156, D157/\.

3-3

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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 ModeNo cassette tape loading SYSTEM/KEY Circuit Auto StopAuto 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-4-4Opener 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 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 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 Is the Belt ok? NonoFront Loading Mechanism Cassette does not load Exploded Views Moving Mechanism A11 RUN Date NSP Not Service PartParts 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