C Circuit, No Video in EE Mode | LG Electronics TL-AT130M instruction

SECTION3 ELECTRICAL

ELECTRICAL TROUBLESHOOTING GUIDE

3. Y/C CIRCUIT

(1) No Video in EE Mode

No Video in EE Mode

Does the Video signal appear at the

IC3G1 Pin9?

YES

NO

Check the Video input Jack &

jack Board connection.

Does the Video signal appear

at the IC301 Pin38?

YES

Is 5V applied to the

IC301 Pin16, 40, 55, 58, 75, 87?

YES

Does the Video signal appear

at the IC301 Pin29?

YES

NO

NO

NO

Check the IC3G1 Pin14

and Q3G1 emitter.

Check the 5VA Line.

(Power Circuit)

Is I2C BUS signal applied to the

IC301 Pin 23, 24?

YES

NO

Check the System Circuit. (Refer to

‘SYSTEM I2C BUS Trouble Shooting’)

Does the Video signal appear

at the IC501 Pin 47?

YES

Does the Video signal appear at the Emitter terminal of the Q380?

NO

NO

Check the path of the signal between

the IC301 Pin29 and IC501 Pin49.

Is there 9V on the plus terminal of the C381?

YES

Replace the Q380.

NO

NO

Check C316.(AGC)

YES

Replace the IC301.

Check the 9V Line.

(Power Circuit)

3-6

Image 16

LG Electronics TL-AT130M service manual C Circuit, No Video in EE Mode

Contents

KEY Table of Contents Summary Front Rear Indicator Panel VCR Function Indication Terminal Signal Levels IN/OUT Description Summary Critical Parts Replacing Time Table Cabinet & Main Frame Exploded Views Cabinet & Main Frame Section Parts list Cabinet and Main Frame Section Packing Accessory Section Parts list Packing & Accessory Section PG Adjustment Connection chart of PG adjustment Power CircuitSMPS No 5.3 a No 24 No 5.2 a to AVCP, Bias Video is unstable in PB mode PB modeWhen the drum moter stop Servo Circuit When the capstan motor stops Capstan motor stops No 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 Circuit No sound in REC Mode No sound in REC Mode No cassette tape loading SYSTEM/KEY Circuit Auto StopAuto Stop No Key display OSD CircuitNo OSD display No F.OSD display Electrical 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.BOARD Mechanism Top View Bottom View Part Fixing Type Drum Assembly Fig. A-1-1 Drum Motor Plate Top Fig. A-2-1 Fig. A-2-4 Gear 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-2-6 Arm Assembly CleanerBase Assembly A/C Head Head F/E Fig. A-3-2 Brake 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-4-4 Opener 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-6-3 Gear Sector Fig. A-7-3 Lever Tension Fig. A-7-5Lever Spring Fig. A-7-6 Just lift the Plate Slider up Gear 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-8-4 Base 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-1 Checking Torque Test Equipment/ Fixture Test ConditionsMechanism Condition Torque Gauge 600g.cm ATG Cassette Torque Meter SRK-VHT-303 Guide Roller Height Adjustment Audio/Control A/C Head Adjustment Adjustment Procedure/DiagramsHead Assembly Head Base Value Adjustment Precise Adjustment Azimuth adjustmentAdjustment Procedure Adjustment Diagram 1KHZ 7KHZ Adjustment after Replacing Drum Assembly Video Heads Check the Tape Travel after Reassembling Deck Assembly Check before starting repairs Required Maintenance Scheduled MaintenanceMaintenance Procedure Cleaning Chassis 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 Screw LOCA.NO Description Specification Remark BATTERY,LITHIUM Electrecal sectionBuzzer Capacitor LOCA.NO Description Specification Remark NP0 TS Coil Diode Digitron FilterFuse Holder R121 0RD1800F608 R3G6 0RD1800F608 R553 0RD2200F608 R610 0RD2701F608 LOCA.NO Description Specification Remote Controller Receiver RemarkSwitch RESISTOR,DRAWING Transformer VaristorTAL Zener Diode