LG Electronics TL-AT130M service manual No sound in REC Mode

Page 20

SECTION3 ELECTRICAL

ELECTRICAL TROUBLESHOOTING GUIDE

(3) No sound in REC Mode.

NO sound in REC Mode.

YES

Sound is not recorded.

YES

Is Playback O.K.?

YES

NO

Refer to "No sound in PB Mode,".

Is the Audio signal applied to the IC301 Pin 76?

YES

Does the Audio waveform appear

at the IC301 Pin 7?

YES

Is 5V applied to the FL401

Pin 2?

YES

NO

NO

NO

Check the path of Line Audio.

Is the “High” signal applied to the

IC301 Pin 10?

YES

Check the IC501 Pin 96

(Audio Mute “H”).

NO

Check the CLK/Date line and

replace the IC301

Is 3.0~4.5V applied to the Emitter					Check the line of the 5V
of the Q481?					Power Circuit.
				NO
YES				NO

Does the Erase signal
appear at the FL401 Pin 6?
				NO
YES




Is the Voltage level of the IC301					Replace the FL401 or the
Pin6 850mVp-p?					Q405.
				NO
				NO

Check the Audio R/P/E connector and Head.

3-10

Image 20

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 Video is unstable in PB mode PB modeWhen the drum moter stop Servo CircuitWhen the capstan motor stops Capstan motor stopsC Circuit No Video in EE ModeNo Video in EE Mode 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 CircuitNo sound in REC Mode No sound in REC ModeAuto Stop SYSTEM/KEY Circuit Auto StopNo cassette tape loading No Key display OSD CircuitNo 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 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-2-4Gear 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-2-6Arm Assembly CleanerBase Assembly A/C Head Head F/E Fig. A-3-2Brake 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-4-4Lever 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 Brake Assembly Capstan Lever F/R Fig. A-6-3Gear Sector Fig. A-7-3 Lever Tension Fig. A-7-5Lever Spring Fig. A-7-6 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 Loading Fig. A-9-1 Arm Assembly Idler Fig. A-9-3 Arm Assembly IdlerBase Tension Fig. A-9-2 Base Tension Base LoadingDeck Mechanism Adjustment Mechanism Alignment Position Check Fig. C-1Checking Torque Test Equipment/ Fixture Test ConditionsMechanism Condition Torque Gauge 600g.cm ATG Cassette Torque Meter SRK-VHT-303Guide Roller Height Adjustment Audio/Control A/C Head Adjustment Adjustment Procedure/DiagramsHead Assembly Head BaseValue Adjustment Precise Adjustment Azimuth adjustmentAdjustment Procedure Adjustment Diagram 1KHZ 7KHZAdjustment after Replacing Drum Assembly Video Heads Check the Tape Travel after Reassembling Deck AssemblyCheck before starting repairs Required Maintenance Scheduled 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 Nono Is the Belt ok?Front Loading Mechanism Cassette does not load Exploded Views Moving Mechanism A11 Parts Section NSP Not Service PartRUN Date Description Specification Assembly Section RemarksLOCA.NO Description Specification Remarks ScrewLOCA.NO Description Specification Remark BATTERY,LITHIUM Electrecal sectionBuzzer CapacitorLOCA.NO Description Specification Remark NP0 TS Coil DiodeDigitron FilterFuse HolderR121 0RD1800F608 R3G6 0RD1800F608 R553 0RD2200F608 R610 0RD2701F608 LOCA.NO Description Specification Remote Controller Receiver RemarkSwitch RESISTOR,DRAWINGTransformer VaristorTAL Zener Diode