LG Electronics TL-AT130M service manual Pin 16, 40, 55, 58, 87?

Page 17

SECTION3 ELECTRICAL

ELECTRICAL TROUBLESHOOTING GUIDE

(2) When the Y(Luminance)signal doesn’t appear on the screen in PB Mode.

Is 5V applied to the IC301

Pin 16, 40, 55, 58, 87?

Is the I2C Bus signal applied

to the IC301 Pin 23, 24?

YES

NO

NO

Check the line of the 5.3VA

Line. (Power Circuit)

Check the System Circuit. (Refer to

‘SYSTEM I2C BUS Trouble Shooting’)

Does the normal RF signal	NO
Does the normal RF signal
appear at the IC301 Pin74?
appear at the IC301 Pin74?

YES

Is the V.H.S/W "H" about 3.4V to the IC301 Pin11 ?

YES

Is V.H.S/W "H" about 3.4V at the IC301 Pin 11?

YES

Clean the Drum.

NO

NO

NO

Check the System Circuit.

(IC501 Pin 23)

Check the V.H.S/W level. (Check R304, R305)

Replace the IC301.

Does the Y(Luminance) RF signal	NO
appear at the IC301 Pin 17?
appear at the IC301 Pin 17?

YES

NO

Is the Y(Luminance) Video waveform

showed up at the IC301 Pin 41?


Check the path of the Y(Luminance)	YES
RF signal.(Check the Q301)
RF signal.(Check the Q301)


Check the path of the Y(Luminance)	YES
RF signal.(Check Q302, Q303)
RF signal.(Check Q302, Q303)

YES

Replace the IC301.

3-7

Image 17

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 stopsC Circuit No Video in EE ModeNo Video in EE Mode 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 ModeAuto Stop SYSTEM/KEY Circuit Auto StopNo cassette tape loading 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-4-4Lever T/up Fig. A-5-4 Arm T/up Fig. A-5-5 Arm Assembly Pinch Fig. A-5-3Opener Lid Fig. A-5-2 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 CleaningGear Sector Gear Cam Base Loading Gear Drive GreasingChassis Bottom Chassis Top Base, Tension Lever, F/R, Base, TensionGear AY, P2 & P3 Mechanism Troubleshooting Guide Auto Stop PLAY/CUE/REV Is the Belt ok? NonoFront Loading Mechanism Cassette does not load Exploded Views Moving Mechanism A11 Parts Section NSP Not Service PartRUN Date 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