Power Supply Check, Input/Output Levels and Impedance | Sony LX50

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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Sony LX50, LX70S, RMT-V293A, RMT-V294A, LX60S, LX40 service manual Power Supply Check, Input/Output Levels and Impedance

Contents

RMT-V293A/V294A Specifications Safety CHECK-OUT Service Note Table of ContentsDisassembly Adjustments Block Diagrams Error Code Indication Service Note Hookups Setting up the remote commander Hookup Antenna hookup Hookup 1 VCR setupCompleting A/V hookup Hookup Hookup Connecting a cable box with many scrambled channels Hookup 2 VCR setupHookup 3 VCR setup Automatic clock setting Selecting a language Setting the clockUsing the Auto Clock Set feature If the clock does not activate Using Manual Clock Set Presetting/disabling channels manually Presetting channelsPresetting all receivable channels automatically If the picture is not clear Playing a tape Recording TV programs To watch another TV program while recording Recording TV programs using the Dial TimerTo save a recording Before you start About the Demonstration Mode Recording TV programs using the timer Locking the VCR Child Lock Playing/searching at various speedsTo resume normal playback To lock the VCR Checking/changing/canceling timer settings Setting the recording duration timeRecording stereo programs Recording bilingual programs Searching 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 tape Press 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 function Operation when recording on this VCR How to connect to record on this VCREditing with another VCR Before you start editing Index to parts and controls General setup information Rear panel Display window 11--19E CASE, Front Panel Block Assembly SLV-LX40/LX50/LX60S/LX70S Section Disassembly Rear 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 a Frame 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 Diagram Audio 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 BOARD5/7 Display 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 Block Drum FG REC/PBDrum PG OSD V OUT Line 2 Line 2FJ-32 Board DI-80 Board Dial TimerDial Timer System Control Mechanism Block Interface MA-405 Board IC160 Signal Pin No System 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 Check VTR Audio System AdjustmentServo System Check ACE Head Adjustment VIDEO/AUDIO Line IN/OUT Adjusting Parts Location DiagramSW5V RF/HF SWP Front Panel and Upper Case Section Exploded Views 5455 Chassis Section 721 711 720 713 725 724 714 719 715 717 718 Mechanism Deck707 708 712 706 702 701 709 704 710 705 722 703 Brake ASSY,MAINT Spring Power TensionRoller ASSY, Guide Spring Screw + P2.6 x 6 TYPE2 NON-SLIT 803 802 833 SWITCH, Tact SwitchLX70SCL,CS Connector Resistor Double Layer MA-405 Film CeramicMylar PIN, Connector 4P CONNECTOR, FFC/FPC 5PHOUSING, Connector 6P LX40/LX50 CONNECTOR, FFC/FPC 7P TUBE, Fluorescent Indicator FILTER, Line Fluorescent Indicator TubeShort Jumper Selector Short Coil Transistor PT380F3 TransistorTransistor 2SC1815GR-TPE2 Transistor 2SC2712Y-TE85L Metal Oxide SWITCH, Tact 0REW SWITCH, Rotary ModeSWITCH, Tact Ppause SWITCH, Tact ·PLAY Ref. No Description Remarks Ref. No Published by Quality Assurance Dept Sony Corporation