Sony LX50, LX70S, RMT-V293A, RMT-V294A, LX60S Power Supply Check, Input/Output Levels and Impedance

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2-1-5. Input/Output Levels and Impedance

Video input: LINE IN

Input signal: 1 Vp-p, 75 ohms, unbalanced, sync negative

Video output: LINE OUT

Output signal: 1 Vp-p, 75 ohms, unbalanced, sync negative

Audio input: LINE IN

Input level: –7.5 dBs (0 dBs= 0.775 Vrms)

Input impedance: more than 47 kilohms Audio output:LINE OUT

Standard level: –7.5 dBs at load impedance 47 kilohms

Output impedance: less than 10 kilohms

2-1-6. Adjustment Sequence

The adjustments should be performed in the following sequence.

Power Supply Check

Servo/Video System Adjustments

Audio System Adjustments

2-2.	POWER SUPPLY CHECK
2-2-1.	Output Voltage Check (MA-405 Board)
Mode		STANDBY

+30 V Check

Measurement point		C671 3

Specified value		31.0 to 39.0 V

–11 V Check

Measurement point		Anode of D420

Specified value		–12.5 to – 9.5 V

D+6 V Check

Measurement point		Collector of Q674

Specified value		5.56 to 6.25 V

Mode		E-E

Measuring Instrument		Digital voltmeter

SW+12 V Check

Measurement point		IC660 pin 2

Specified value		11.7 to 12.3 V

SW+5 V Check

Measurement point		Emitter of Q662

Specified value		4.8 to 5.4 V

MTR12 V Check

Measurement point		Collector of Q600

Specified value		12.5 to 14.5 V

F Check

Measurement point		ND420 e; to 1

Specified value		2.0 to 5.0V

[Check Method]

1)Each of these supply voltages must meet its specified value.

6-2

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Contents RMT-V293A/V294A SpecificationsSafety CHECK-OUT Service Note Table of ContentsDisassembly Adjustments Block DiagramsError Code Indication Service NoteHookups Setting up the remote commanderHookup Antenna hookup Hookup 1 VCR setupCompleting A/V hookup HookupHookup Connecting a cable box with many scrambled channels Hookup 2 VCR setupHookup 3 VCR setup Automatic clock settingSelecting a language Setting the clockUsing the Auto Clock Set feature If the clock does not activate Using Manual Clock SetPresetting/disabling channels manually Presetting channelsPresetting all receivable channels automatically If the picture is not clear Playing a tapeRecording TV programs To watch another TV program while recording Recording TV programs using the Dial TimerTo save a recording Before you startAbout the Demonstration Mode Recording TV programs using the timerLocking the VCR Child Lock Playing/searching at various speedsTo resume normal playback To lock the VCRChecking/changing/canceling timer settings Setting the recording duration timeRecording stereo programs Recording bilingual programsSearching using the index function Searching for the beginning of a timer recorded programSearching using the Time Search function How sound is recorded on a video tapePress H Play or x Stop To cancel skip-searchSearch forward while Showing the tape contents Fast-forward Adjusting the tracking Adjusting the pictureChanging menu options About the Adaptive Picture Control APC functionOperation when recording on this VCR How to connect to record on this VCREditing with another VCR Before you start editingIndex to parts and controls General setup informationRear panel Display window11--19E CASE, Front Panel Block Assembly SLV-LX40/LX50/LX60S/LX70S Section DisassemblyRear Panel Mechansim Deck Bottom View Internal ViewsTop View Circuit Boards Location Overall Block Diagram Video Block Diagram SERVO/SYSTEM Control Block Diagram Tuner Block Diagram Audio Block Diagram Power Block Diagram Xedit → Edit PB/XREC → PB/REC TA aFrame Schematic Diagram VIDEO, AUDIO, SERVO/SYSTEM CONTROL, TUNER, Power See page 4-21 for waveforms MA-405 BOARD1/7 MA-405 REC/PB Head AMP Schematic DiagramREC/PB Head AMP Audio Processor VA Block MA-405 Y/C, Audio Processor Schematic DiagramAudio Process SERVO/SYSTEM Control SS Block MA-405 SERVO/SYSTEM Control Schematic DiagramAudio Process AU Block MA-405 Audio Process Schematic DiagramSee page 4-5 for printed wiring board MA-405 BOARD4/7 See page 4-5 for printed wiring board MA-405 Tuner Schematic DiagramTuner MA-405 BOARD5/7Display Control Front Block MA-405 Display Control Schematic DiagramSee page 4-5 for printed wiring board MA-405 BOARD6/7 MA-405 Power Supply Schematic Diagram Power SupplySee page 4-5 for printed wiring board MA-405 BOARD7/7 Power Supply PS BlockDrum FG REC/PBDrum PG OSD V OUTLine 2 Line 2FJ-32 Board DI-80 Board Dial TimerDial Timer System Control Mechanism Block Interface MA-405 Board IC160 Signal Pin NoSystem Control Audio Block Interface MA-405 Board IC160 System Control VIDEO/RP Block Interface MA-405 Board IC160 Pin Name Function 55-4E Preparation Before Adjustment Mechanical AdjustmentsElectrical Adjustments Input/Output Levels and Impedance Power Supply CheckVTR Audio System AdjustmentServo System Check ACE Head Adjustment VIDEO/AUDIO Line IN/OUT Adjusting Parts Location DiagramSW5V RF/HF SWPFront Panel and Upper Case Section Exploded Views5455 Chassis Section721 711 720 713 725 724 714 719 715 717 718 Mechanism Deck707 708 712 706 702 701 709 704 710 705 722 703 Brake ASSY,MAINT Spring Power TensionRoller ASSY, Guide SpringScrew + P2.6 x 6 TYPE2 NON-SLIT 803 802 833SWITCH, Tact SwitchLX70SCL,CS Connector ResistorDouble Layer MA-405Film CeramicMylar PIN, Connector 4P CONNECTOR, FFC/FPC 5PHOUSING, Connector 6P LX40/LX50 CONNECTOR, FFC/FPC 7PTUBE, Fluorescent Indicator FILTER, Line Fluorescent Indicator TubeShort Jumper Selector Short CoilTransistor PT380F3 TransistorTransistor 2SC1815GR-TPE2 Transistor 2SC2712Y-TE85LMetal Oxide SWITCH, Tact 0REW SWITCH, Rotary ModeSWITCH, Tact Ppause SWITCH, Tact ·PLAYRef. No Description Remarks Ref. No Published by Quality Assurance Dept Sony Corporation