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LG EC290SW, Service Manual

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SERVICE MANUAL

VIDEO CASSETTE
RECORDER

SERVICE MANUAL

MODELS : EC290W/EC290SW/EC470W/

EC490SW/EC970W/EC990SW

CAUTION

BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.

EC470W/970W

EC290W/290SW/490SW/990SW

MODELS : EC290W/EC290SW/EC470W/EC490SW/EC970W/EC990SW

SER

VICE MANUAL

Summary of Contents for EC290SW

Page 1: ...VICE MANUAL MODELS EC290W EC290SW EC470W EC490SW EC970W EC990SW CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL EC470W 970W EC290W 290SW 490SW 990SW MODELS EC290W EC290SW EC470W EC490SW EC970W EC990SW SERVICE MANUAL ...

Page 2: ...DURES 3 2 1 Servo Circuit 3 2 ELECTRICAL TROUBLESHOOTING GUIDE 3 4 1 Power Circuit SMPS 3 4 2 Servo Circuit 3 7 3 System Front Panel Circuit 3 10 4 Y C Circuit 3 13 5 Tuner IF Circuit 3 17 6 Hi Fi Circuit 3 20 BLOCK DIAGRAMS 3 22 1 Power Block Diagram 3 22 2 Tuner IF NICAM A2 Block Diagram 3 24 3 Y C Block Diagram 3 26 4 Hi Fi Block Diagram 3 27 5 System Block Diagram 3 28 CIRCUIT DIAGRAMS 3 30 1 ...

Page 3: ... LD LED LD VTG CTL Loading Voltage Control LECHA Letter Character L M Level Meter LP Long Play LPF Low Pass Filter M MAX Maximum MD Modulator MECHA CTL Mechanism Control MIC Microphone MIN Minimum MIX Mixer Mixing M M Monostable Multivibrator MMV Mono Multi Vibrator MOD Modulation Modulator MODEM Modulator Demodulator MPX Multiplex N NR Noise Reduction O OSC Oscillator OSD On Screen Display P PB P...

Page 4: ...s and those specified for compliance with various regulations regarding spurious radiation emission 3 Use Specified internal wiring Note especially 1 Double insulated wires 2 High voltage leads 4 Use specified insulating materials for hazardous live parts Note especially 1 Insulation Tape 2 PVC tubing 3 Spacers 4 Insulation sheets for transistor 5 Observe that wires do not contact heat producing p...

Page 5: ...el only Note This table is unofficial and for reference only Be sure to confirm the precise values for your particular country and locality Leakage Current test Confirm specified or lower leakage current between B earth ground power cord plug prongs and externally exposed accessible parts RF terminals antenna terminals video and audio input and output terminals micro phone jacks earphone jacks etc...

Page 6: ...ontrol are switched to Low As a result POWER Switching TR is kept from generating heat and fire POWER for each IC S 5V POWER SECAM IC Series 5VT POWER AVCP IC P Y I 5V POWER Modulator Series 5VT POWER AVCP IC Short protection off mode DJ01 Diode in PROPOSAL FOR APPLYING SHORT PROTECTION IIC BUS 5VT SW POWER CONTROL MASTER TIMER CONTROL 5VT SW SLAVE with 5V SLAVE with 5V 5 3VA Timer Control AVCP IC...

Page 7: ...r being switch all and no tapes OK is displayed at FLD for FLD models and LED becomes on for LED CLOCK models This is the state that initializing EEPROM is finished In case of PAL VCP if holding the REC button on the front panel and the MENU button on the remote control handset for 5 7 seconds with power being off and no tapes All the LED DOTs become on This is the state that initializing EEPROM i...

Page 8: ...0 lbs 4 0 kg Operating temperature 41 F 95 F 5 C 35 C Operating humidity Less than 80 Timer 24 hours display type Video Input level VIDEO IN RCA type 1 0 Vp p 75 ohm unbalanced Output level VIDEO OUT RCA type 1 0 Vp p 75 ohm unbalanced Signal to noise ratio More than 43 dBm RF Modulator UHF 28 68 Adjustable Audio Input level AUDIO IN RCA type 6 0dBm more than 47kΩ Output level AUDIO OUT RCA type 6...

Page 9: ...e unit according to No 2 Re assembly Flow 3 Place the unit like Fig 2 1 4 Check and replace Electrical parts NOTE 1 Insert Video Cassette Tape inversely like Fig 2 1 to check and replace defective parts 2 In disassembling and reassembling be careful not to damaged CST switch Top Case Bottom Cover Front Panel Housing Deck Assembly Main C B A LED C B A LED C B A Main C B A Housing Deck Assembly Hous...

Page 10: ...d Main Frame Section 283 280 284 261 260 457 A00 464 462 462 250 300 A43 330 452 457 320 A46 A42 A49 A 5 4 3 2 1 B C D NOTE Refer to SECTION 5 REPLACEMENT PARTS LIST in order to look for the part number of each part _ OPTIONAL PARTS ...

Page 11: ...ERY 808 806 PLUG ASS Y 2WAY Optional parts 812 PLUG ASS Y 1WAY Optional parts 811 REMOCON 900 PACKING RF 803 PACKING LF 803 BOX CARTON 802 BAG SOFR SHEET 804 INSTRUCTION MANUAL 801 NOTE Refer to SECTION REPLACEMENT PARTS LIST NOTE in order to look for the part number of each part 2 3 ...

Page 12: ... M P S SYSTEM A V DECK CNT A V JACK T U N E R TUNER MODULATOR SMPS LED DRIVE CLK DOT DISP KEY BOARD L KEY BOARD R 3 4 CH SWITCH Measurement point Adjustment point SECTION 3 ELECTRICAL ELECTRICAL ADJUSTMENT POINTS ARRANGEMENT ...

Page 13: ... a Initial c Press the Auto PG Key on JIG Remocon again 2 nd or press Play key on set and 0 key on Remocon again Then check the blink PG NG PG OK on CLK LED Hi Fi Model Then check the blink PG waveform on oscilloscope MONO Model Check the PG a Connect the CH1 of the oscilloscope to the H SW and CD2 to the Video out for the VCR b Trigger the mixed Video Signal of CH2 to the CH1 H SW W714 W715 and t...

Page 14: ...LECTRICAL ADJUSTMENT PROCEDURES WAVEFORM Attension and Reference a The PG checking must do when RF Level is Maximum and SERVO system is Locking MTR MODE b V H SW Level is 2Vpp H SW Composite VIDEO 6 5H 416us ...

Page 15: ... 7 Is there DC voltage at the IC101 Pin 4 Is there about 2 5V at the IC103 Vref Is the D106 normal Check the Main PCB 5 3VA Line short Replace the F101 Use the same Fuse Replace the BD101 Replace the R101 Is Vcc about 13 15V permittable at the IC101 Pin 3 Check or Replace the D103 Replace the IC102 Replace the IC103 Replace the D106 NO YES YES YES YES YES YES YES YES NO NO NO NO NO NO NO ...

Page 16: ...es 5 3VA work normally Check whether 5 3VA is out of order YES NO NO 7 Power Circuit SMPS 2 No 12VA Capstan 3 No 12V Hi Fi Buffer Is Voltage about 13V put into the Q152 B Check or Replace the Q152 YES YES No 12VA Is Vcc about 12V put into the Q152 E Replace the Peripheral Circuitry of ZD152 YES NO ...

Page 17: ...Is about 4 7V put into the Q155 Q157 Base Check the Q156 whether it works normally Check or Replace the Q155 Q157 YES YES No 5V Is the Q156 Base H Is 5 3VA put into the Q155 Q157 collector Check the µ com Control YES YES NO NO 3 6 ...

Page 18: ...ar at IC501 pin 97 Does the CFG divide waveform appear at IC501 pin 87 Do the CTL pulses move when TRK is operated Replace IC501 Does the Video Envelope waveform appear at IC501 Pin 9 NO YES YES YES YES YES A Is the height of the CTL Head adjusted correctly NO Replace IC501 NO Check Y C Block NO Adjust the CTL Head ...

Page 19: ...the Drum PWM waveform appear at IC501 Pin 76 Check the Components and foil Pattern Connected to IC501 Pin 76 PMC01 Pin 12 for shorts Do DPG FG Pulses appear at IC501 Pin 90 B NO NO NO NO Check Power Does Drum PWM appear at IC501 Pin 76 Do DPG FG Pulses appear at PMC01 Pin 11 Check Drum Monitor Ass y Check the Components and foil pattern between PMC01 Pin 11 and IC501 Pin 90 for shorts Replace IC50...

Page 20: ...ce IC501 Does 12VA appear at PMC01 Pin 2 Does 2 8V appear at PMC01 Pin 9 Check Connector and Capstan Motor Ass y Check the Components and foil Patterns Connected between IC501 Pin 77 and PMC01 Pin 9 for shorts Does the CFG signal appear at IC501 Pin 87 Does Capstan PWM appear at IC501 Pin 77 Check the components and foil pattern connected between IC501 Pin 77 and PMC01 Pin 9 for shorts C NO NO NO ...

Page 21: ...r on Main PWB Board RS501 Check the Power Check the Drum Motor Signal Auto stop Does SW30 waveform appear at IC501 Pin 18 Do Take up reel pulses appear at IC501 Pin 80 Change IC501 A NO NO NO YES 3 System Front Panel Circuit Does 5 3V appear at RS501 ...

Page 22: ...CST Does Low signal occur form IC501 Pin 60 when inserting the CST Check the Deck Mechanism NOTE Auto stop may also be caused by lack of lubrication due to dried grease or oil Is 5 3V applied to R544 Check the power Check IC501 Pins 22 23 24 25 Change IC501 Check the CST SW and peripheral circuitry Check the power B NO NO NO YES NO YES YES ...

Page 23: ...C YES YES NO NO LED CLOCK LED DOT doesn t work Is 5V applied to IC501 Pins 37 and IC5F1 Pins 5 18 Check the OPTION 1 Do pulse appear at IC501 Pins 65 66 and 67 Replace IC501 Check the power circuit D YES YES Do oscillation appear at IC5F1 Pin1 YES Check the foil patterns between IV5F1 and OPTION2 YES OPTION 1 D5E4 LED CLOCK OPTION 2 LED 501 LED CLOCK LED 502 LED DOT Replace OPTION 2 YES NO NO Repl...

Page 24: ...Pin 50 Does the Video signal appear at the Emitter termi nal of the Q701 Check the 5 2V 5 4VA Line Power Circuit Is I2 C BUS signal applied to the IC301 Pins 68 69 Check C316 AGC Chck the path of the signal between the IC301 Pin 5 and IC501 Pin 50 Replace the IC301 Does the 12V appear at the Emitter terminal of the Q701 Replace the Q701 Check the 12V Line Power Circuit Check the System Circuit Ref...

Page 25: ...in 18 Check the V H S W level Check R303 R304 Replace the IC301 Refer to SYSTEM I2 C BUS CHECK Trouble Shooting Is the V H S W signal applied to the IC301 Pin 70 Is V H S W H about 3 4V at the IC301 Pin 70 Clean the Drum Check the path of the Y Luminance RF signal Check C327 Check the path of the Y Luminance RF signal Check the C312 Does the Y Luminance RF signal appear at the IC301 Pin 76 Is the ...

Page 26: ...e Color signal appear at the IC301 Pin 25 Check the line of the 5 2V 5 3VA Line Power Circuit Replace the X301 Check the Color Pass Check the Color Rotary Circuit IC501 pin 15 Check the Color Rotary level Check the R303 Does the X301 4 43MHZ oscillate Replace the IC301 Does the Color signal appear at the IC301 Pin 21 Is Color Rotary H about 3 4V Replace the IC301 NO YES YES YES YES NO NO NO NO NO ...

Page 27: ...e System of REC H the IC501 Pin 74 the D301 Replace the IC301 Check the line of the 5 2V 5 3VA Line Power Circuit Check PB Mode Is the REC H signal about 4V applied to the IC301 Pin 80 Check the circuit of the IC301 Pins 85 86 Check REC Luminance Pass Color Pass Does PB Mdoe operate normally Does the REC RF signal appear at the IC301 Pins 88 89 94 95 Check the Drum Drum Connector YES YES YES YES Y...

Page 28: ...Is 30V applied to TU701 Pin 16 Is 5 2V applied to TU701 Pin 13 Does the Clock signal appear at TU701 Pin 11 Does the data signal appear at TU701 Pin 12 Replace Tuner Check the signal flow from TU701 Pin 24 to IC301 Pin 48 Does the Video signal at the IC501 Pin50 Check the signal flow from IC501 Pin52 to JK301 YES YES YES YES YES YES YES NO NO NO NO NO Check the liC Data signal of µ com Pin 72 NO ...

Page 29: ...C301 Pin 18 Check the Tuner Audio signal at IC301 Pin 13 Check the Audio signal at IC301 Pin 11 Check 5 2V power Chekc the signal flow from TU701 Pin21 to IC301 Pin 13 Replace IC301 NO NO NO YES YES YES Check the signal flow from IC301 pin 11 to JK301 YES ...

Page 30: ...heck the Audio of IC801 Pins 2 3 Check the Audio of IC801 Pins 18 19 Check the signal flow from IC801 pins 18 19 to JK301 Check 5V power Check the Tuner Audio of TU701 Pin 21 Replace X751 Check the IIC Clock and Data at IC751 Pins 12 13 Check the signal flow from IC751 Pins 30 31 to IC801 Pins 2 3 Check the IIC Clock and Data at IC801 Pins 42 43 YES YES YES YES YES YES YES NO NO NO NO NO NO ...

Page 31: ...hen Replace IC801 Check Ports of µ COM Replace IC801 Hi Fi Playback No sound Check the Hi Fi Selection Switch and the Tape quality Is the RF Envelope at IC801 Pin 44 over 2Vp p Check the Signal path of Audio Output Do Audio signals appear at IC801 Pin 16 L CH 17 R CH Check IC801 Pin 42 Data Pin 43 Clock A YES NO YES NO NO NO NO 6 Hi Fi Circuit Hi Fi Model YES YES YES YES YES ...

Page 32: ...k ports of µ COM Check Audio input signal of IC801 Pins 2 3 TU A 6 7 Scart 1 Replace IC801 B Check IC801 Pin 42 Data Pin 43 CLOCK Do Audio signals appear at IC801 Pins 16 17 YES YES YES Do FM Audio signals appear at IC801 Pin 36 Check the Contact Points of Drum Connector if good then Replace the Drum YES YES NO NO NO NO ...

Page 33: ...M D152 D154 D155 D151 SNUBBER BLOCK IC101 R109 C135 D103 R103 C109 R125 R126 D102 R104 C105 C106 D109 C120 L104 C121 NOTES Symbol denotes AC ground Symbol denotes DC chassis ground FROM µ COM P CTL H LINE FILTER BLOCK C101 L102 C102 RECTIFIER SMOOTHING D105 C115 34V S W BLOCK Q154 R154 R155 5VT SW BLOCK Q157 R170 R171 D157 5V S W BLOCK PWR CTL BLOCK Q155 R156 R157 D158 Q162 R161 FEED BACK BLOCK R1...

Page 34: ...3 24 3 25 2 Tu IF NICAM A2 Block Diagram 34V From Power 109 100 731 72 71 73 106 109 52 109 871 108 5 4VA 733 V out 5 2V V IN IC751 MSP3417 MSP3407 ...

Page 35: ...5 70 69 68 67 65 59 58 54 52 50 V IN2 S1 V IN1 TUNER 48 46 43 33 32 31 CLK IN 29 28 4 43MHz 27 21 95 94 89 88 Killer C LPF ACC BPF Main Conv Main Conv DETAIL ENH NL EMPHA W D CLIP IC301 LA71750M UP REC SP REC To Drum To Drum W D CLIP REC FM EQ Y LPF FBC AGC SW Y DELAY KILL DEC REC APC VX02 VX02 COMP AMP 1H 2H DELAY YNR 4 Hi Fi Block Diagram 1 2 3 4 5 6 7 8 9 10 13 16 17 19 20 21 35 36 37 22 32 33 ...

Page 36: ...37 98 34 IC501 M37760 MODE S1 I Limit MODE S2 MODE S3 MODE S4 T UP Sensor T UP Reel SUP Reel CST IN Vss AMP Vss OSD Vss SYSCON Vcc SYSCON Vcc SERVO CAP PWM CTL CTL CFG CAP REV H CAP ACCEL LD LD V ENV V H SW30 DPG D V Sync CVin EDS 38 39 X out Xc in Xc out X in 35 36 53 52 44 fsc IN fsc OUT OSC in 2 95 94 87 12 59 60 83 9 18 56 76 90 13 77 11 DRUM PWM 53 Vcc OSD 84 SUP Sensor 45 OSC out 2 14 99 Vcc...

Page 37: ...E electricial shock BD101 R101 are defective Power is dead F101 is defective Power dead IC101 is defective Switching dead D102 is defective No power D106 is defective No 5 3VA and 5 1V No 12VA and 12V D109 C120 are defective IC102 IC103 are defective Power dead NOTE 1 Shaded parts are critical for safety Replace only with specified part number 2 Voltages are DC measured with a digital voltmeter du...

Page 38: ...3 32 3 33 2 Tuner NICAM A2 Circuit Diagram EE MODE VIDEO TU MODE AUDIO ...

Page 39: ...cking is failed IC301 Pin 84 is defective PB COLOR Signal disappear IC301 Pin70 is defective PB COLOR Signal disappear X301 is defective D301 or IC301 Pin 80 REC is defective PB and Recording is failed IC301 doesn t operate IC301 Pin 69 68 are defective Normal Audio signal is not recorded FL301 Q301 Q306 are defective No mono Audio Signal in PB MODE Q302 Q303 Q304 are defective ...

Page 40: ...ve OSD will not operate L511 R598 C595 C596 are defective µ COM is unstable Q501 Q503 are defective Remote control is Pulse coil not Receive RC501 is defective VCR will not operate IC505 is defective Deck will not operater R575 R576 R577 R578 are defective Reset is defect Set dead IC504 is defective Auto stop occurs RS501 RS502 are defective Auto rew will not working ES501 Es502 LD501 are defectiv...

Page 41: ...3 38 3 39 5 Hi Fi Circuit Diagram RF Hi Fi NORMAL AUDIO V out V in All Audio is not appear IC801 42 43 Pins are defective ...

Page 42: ... IC301 Pins 71 72 REC mode 340mVp p IC301 Pins 51 54 PB mode 300mVp p IC301 Pin 63 PB mode 400mVp p IC301 Pin 11 PB mode 3 6Vp p _ IC301 Oscilloscope Waveform IC501 Waveform photographs IC501 Pin 14 1V 5mS REC PB modes V H SW IC501 Pin 27 1V 2mS QUE REV modes D V SYNC IC501 Pin 31 1V 10mS REC mode CTL IC501 Pin 32 1V 10mS REC mode CTL IC501 Pin 45 500MV 10uS EE PB modes V OUT IC501 Pin 54 1V 20uS ...

Page 43: ... 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 PULSE 0 1 4 0 0 VIDEO VIDEO 5V PULSE 1 VIDEO 0 0 2 6 0 0 PULSE PULSE PULSE 0 0 PULSE PULSE 0 0 3 5 PULSE PULSE 5 PULSE PULSE 0 0 5 PULSE 0 PULSE 2 8 2 6 0 0 0 2 8 PULSE 5 2 5 2 PULSE 0 1 4 0 0 VIDEO VIDEO 4 9 PULSE 1 6 VIDEO 0 0 2 6 0 0 PULSE PULSE PULSE 0 0 PULSE PULSE 0 0 3 5 PULSE PULSE 5 0...

Page 44: ... 84 29 78 0 0 69 5 18 4 38 0 01 5 3 0 01 5 18 0 42 0 4 1 29 5 19 1 98 1 98 2 41 4 54 4 52 32 89 13 35 0 84 29 8 0 0 69 5 18 4 38 0 01 4 41 0 4 52 0 69 0 71 1 83 5 16 1 98 1 96 2 37 4 55 4 51 33 12 13 42 0 84 30 13 0 0 69 5 18 4 38 0 01 4 4 0 75 5 13 24 85 24 7 1 81 2 14 1 93 1 93 2 33 5 24 5 22 32 97 14 05 4 38 13 21 29 82 0 0 03 0 01 14 04 5 11 5 15 0 42 0 0 0 5 19 0 0 0 5 24 5 22 33 5 13 77 4 38...

Page 45: ...3 46 3 47 LOCATION GUIDE PRINTED CIRCUIT BOARD DIAGRAMS 1 MAIN P C Board Solder Side ...

Page 46: ...3 48 3 49 LOCATION GUIDE 2 KEY LEFT P C Board Solder Side ...

Page 47: ...tment 4 14 3 Checking Torque 4 14 4 Guide Roller Height Adjustment 4 15 4 1 Preliminary Adjustment 4 15 4 2 Precise Adjustment 4 15 5 Audio Control A C Head Adjustment 4 16 5 1 Preliminary Adjustment 4 16 5 2 Confirmation of Tape Path between Pinch Roller and Take up Guide 4 17 5 3 Precise Adjustment Azimuth Adjustment 4 17 6 X Value Adjustment 4 17 7 Adjustment after Replacing Drum Assembly Video...

Page 48: ...ssembly P4 Chassis Embossing A 5 T 17 Opener Lid Chassis Embossing A 5 T 17 18 Arm Assembly Pinch Shaft A 5 T 17 19 Lever T Up Arm T Up 1 Hook A 5 T 17 18 20 Belt Capstan Motor Capstan 3 Screw A 6 B 21 Lever F R Locking Tab A 6 B 20 21 22 Clutch Assembly D35 Washer A 6 B 23 Break Assembly Capstan Locking Tab A 6 B 24 Gear Drive Gear Cam Washer Hook A 7 B 25 Gear Sector 1 Hook A 7 B 20 21 23 26 Pla...

Page 49: ...e the Drum assembly 3 Unhook H1 H2 and separate the Holder FPC and Cap FPC 1 1 Drum Motor 1 Remove two Screws S2 and disassemble the Stator of the Drum Motor 2 Remove two Screws S3 and separate the Rotor of the Drum Motor from the Drum Sub assembly When reassembling confirm A portion of the Drum Sub assembly whether the Carbon Brush is in there or not Fig A 1 NOTE Fig B 1 Holder FPC Drum FPC Cap F...

Page 50: ...e Top Arm Assembly F L Spring Lever S W Gear Assembly Rack F L Chassis Opener Door Brackert Assembly L D Motor Holder Assembly CST B C D E H6 A B Lever Assembly S W H8 Fig A 2 Fig A 2 1 Fig A 2 2 Fig A 2 6 Fig A 2 7 Fig A 2 5 Fig A 2 3 Fig A 2 4 ...

Page 51: ...remove it through the guide hole of the chassis 5 Bracket assembly L D Motor Fig A 2 4 1 Unplug the Connector C1 2 Unhook three Hooks H3 H4 H5 on bottom side of the Chassis lift up the Bracket assembly L M and disassem ble the Bracket assembly L D Motor 6 Gear Assembly Rack F L Fig A 2 5 1 Move the Gear Assembly Rack F L in direction of arrow A and unhook the Hook H6 pulling back in front 2 Separa...

Page 52: ...e direction and lift it up 10 Head F E Fig A 3 2 1 Breakaway the A portion of the Head F E from the Embossing of the Chassis turn it to counterclockwise direction and lift it up 11 Base assembly A C Head Fig A 3 3 1 Remove the Screw S4 and lift the Base assembly A C Head up A Arm Assembly Cleaner Base Assembly A C Head S4 Head F E A Chassis Fig A 3 Fig A 3 1 Fig A 3 3 Fig A 3 2 ...

Page 53: ...mbly RS Fig A 4 2 1 Unhook the Spring RS from the Hook H10 of the Chassis 2 Lift the Brake assembly T up 14 Arm assembly Tension Fig A 4 3 1 Unhook the Spring Tension from the Hook H11 of the Arm assembly tension 2 Unhook the Hook H12 of the Base Tension and lift the Arm assembly Tension up Difference for Springs 15 Reel S Reel T Fig A 4 4 1 Difference for Reel S Reel T Spring TB Spring RS Spring ...

Page 54: ...akaway the B portion of the Opener Lid from the Embossing of the Chassis 2 Turn the Opener Lid to clockwise direction and lift it up 18 Arm assembly Pinch Fig A 5 3 1 Lift the Arm assembly Pinch up 19 Lever T up Fig A 5 4 Arm T up Fig A 5 5 1 Unhook the Hook H13 of the bottom Chassis and lift the Lever T up up 2 Lift the Arm T up up When reassembling confirm the C portion of the Arm assembly Pinch...

Page 55: ...apstan 2 Remove the three Screws S5 on bottom Chassis and lift the Motor Capstan up 21 Lever F R Fig A 6 3 1 Unlock the Locking Tab L1 as Fig A 6 3 and lift the Lever F R up 22 Clutch assembly D35 Fig A 6 4 1 Remove the Washer W1 and lift the Clutch assembly D35 up 23 Brake assembly Capstan Fig A 6 5 1 Pull the Locking Tab L2 back in direction of arrow and lift it up Fig A 6 1 Fig A 6 2 Fig A 6 3 ...

Page 56: ...he Gear Cam Hole B in a straight line after the Gear Drive Hole C is aligned with the Chassis Hole as Fig 25 Gear Sector Fig A 7 3 1 Unhook the Hook H15 of the Base Loading on bottom Chassis and lift the Gear Sector up 26 Plate Slider Fig A 7 4 1 Just lift the Plate Slider up 27 Lever Tension Fig A 7 5 1 Unhook the A portion of the Lever Tension from the Hook H16 of the Chassis 2 Turn the Lever Te...

Page 57: ...he two Holes of the Gear assem bly P2 and P3 in a straight line after confirmation whether the Gear Sector Hole A and the Plate Slider Hole B are aligned or not as Fig 30 Base assembly P2 Fig A 8 3 Base assembly P3 Fig A 8 4 1 Move the Base assembly P2 in direction of arrow A along the Guided Hole of the Chassis and disassemble it on bottom side 2 Move the Base assembly P3 in direction of arrow B ...

Page 58: ...ion Fig A 9 2 1 Breakaway the A portion of the Base Tension from the Embossing of the Chassis 2 Turn the Base Tension to counterclockwise direction and lift it up 33 Arm assembly Idler Jog Fig A 9 3 1 Make narrower the two parts A and B as Fig A 9 3 2 Lift the Arm assembly Idler up When disassembling be careful not to be caught the D part by the Chassis as Fig NOTE Fig A 9 1 Fig A 9 2 Fig A 9 3 ...

Page 59: ...00 D006 4 Torque gauge adaptor Parts No D09 R001 5 Post height adjusting driver Parts No DTL 0005 6 Type driver ø 5 2 Alignment tape Parts No NTSC DTN 001 PAL DTN 0002 3 Torque gauge 3 600g Cm ATG 3 Parts No D00 D002 SRK VIDEO CASSETTE TORQUE METER VHT 303 S R K V H T S SRK V HT T 300 250 200 150 50 0 300 250 200 150 50 0 100 ...

Page 60: ... is as below Fig C 2 4 Remove the Screw which fixes the Deck Mechanism and Main Frame and confirm if the Gear Cam is aligned with the Gear Drive as below Fig C 1 A 5 Confirm if the Mode S W on the Main P C Board is aligned as below Fig C 1 B 6 Remount the Deck Mechanism on the Main P C Board and check each operation Gear Cam Gear Drive C Mode S W B L D Motor Assembly Gear Cam Chassis Hole Gear Cam...

Page 61: ...aptor with the Torque Gauge affixed The Torque reading to measure occurs when the Tape abruptly changes direction from Fast Forward of Rewind Mode when quick bracking is applied to both Reels SRK VIDEO CASSETTE TORQUE METER VHT 303 S R K V H T S SRK V HT T 300 250 200 150 50 0 300 250 200 150 50 0 100 Test Equipment Fixture Torque Gauge 600g cm ATG Torque Gauge Adaptor Cassette Torque Meter SRK VH...

Page 62: ...velope CH 2 NTSC SW 30Hz PAL SW 25Hz Head Switching Output Point RF Envelope Output Point Test Conditions VCR VCP State Play an Alignment Tape Adjustment Point Guide Roller Height Adjustment Screws Fig C 4 2 Fig C 4 3 P3 POST ADJUSTMENT P2 POST ADJUSTMENT Turn the Roller Guide Height Adjustment Screw slightly to flatten the waveform Tracking control at center RF ENVELOPE OUTPUT TEST POINT OSCILLOS...

Page 63: ...Screw Fig C 5 3 A C Head Tape Tape 0 2 0 25mm P4 5 1 Preliminary Adjustment Height and Tilt Adjustment Perform the Preliminary Adjustment when there is no Audio Output Signal with the Alignment Tape 1 Initially adjust the Base Assembly A C Head as shown Fig C 5 1 by using the Height Adjustment Screw B 2 Play a Blank Tape and observe if the Tape passes accu rately over the A C Head without Tape Cur...

Page 64: ...ly adjust the Azimuth Adjustment Screw A and the Tilt Adjustment Screw C for Maximum Output of the 1Khz and 7Khz segments while maintaining the flattest Envelope differential between the two Frequencies Adjustment Procedure 5 3 Precise Adjustment Azimuth adjustment 6 X Value Adjustment Fig C 5 4 1KHZ Oscilloscope Alignment tape SP only Screw Driver Type 5mm CH 1 PB RF Envelope CH 2 NTSC SW 30Hz PA...

Page 65: ...hanism Condition Play the blank tape Play an alignment tape Adjustment Points Guide Roller Precise Adjustment Switching Point Tracking Preset X Value Checking Adjustment Procedure Play a blank tape and check for tape curling or creasing around the roller guide If there is a problem then follow the procedure 4 Guide Roller Height and 5 Audio Control A C Head Adjustment RF ENVELOPE OUTPUT TEST POINT...

Page 66: ... pinch roller If locations marked with o do not operate normally after cleaning check for wear and replace See the EXPLODED VIEWS at the end of this manual as well as the above illustrations See the Greasing Page 4 22 for the sections to be lubricated and greased NOTE o o o o Dirt on video head Dirt on tape transport system Low volume Sound distorted Tape does not run Tape is slack o In Review and...

Page 67: ...yl Alcohol Touch the cleaning patch to the head tip and gently turn the head rotating cylinder right and left Do not move the cleaning patch vertically Make sure that only the buckskin on the cleaning patch comes into contact with the head Otherwise the head may be dam aged Thoroughly dry the head Then run the test tape If lso propyl Alcohol remains on the video head the tape may be damaged when i...

Page 68: ...1 Loading Path Inside Top side 2 Base Tension Boss inside Hole 3 Arm Assembly F L U Groove 4 Arm Take up Rubbing Section 5 L D Motor Gear Wheel Part 6 Shaft 7 Arm Assembly F L of Buming Inside Hole 8 Reel S T Shaft G381 Yellow 9 Brake T Groove Guide Rail Base Loading Gear Drive Gear Sector Gear Cam Gear Part Bracket Side L Bracket Assembly Door 5 7 8 1 2 6 4 3 1 Loading Path Inside Top side 2 Shaf...

Page 69: ...4 22 GEAR F R GEAR AY P2 P3 ...

Page 70: ...d sensor Check syscon circuit NO YES YES YES NO NO NO 1 Deck Mechanism A NO NO NO No F R modes Is the present mode F R Mode Is the mode SW assembled correctly refer to Pages 4 14 Is the normal voltage supplied to the Capstan Motor Vcc1 Vcc2 Does terminal voltage Vctl of Capstan Motor supply side more than 4V Check Servo Power Circuits Replace the Capstan Motor Does the Capstan Motor rotate Do the ...

Page 71: ...age 4 14 Check spring Pinch Replace Drum Motor Check Servo Syscon Check the Syscon µ COM No cassette loading Insert the cassette Check Holder Assembly CST Is there variation for CST IN S W Output In Tape with REC Tab L H L In Tape without REC Tab L H L H Does the CST IN S W work normally Does the lever Assembly S W work normally Check Syscon Circuit Check Syscon Circuit Replace CST IN S W YES YES ...

Page 72: ...ensors ok Check Syscon Circuit Check Syscon Circuit Check Servo Syscon Does the Capstan Motor turn Is the terminal voltage of the Drum Motor more than 2 3V Replace the Drum Motor Is the Vcc voltage of the Drum Motor normal Check the clutch and the Idler Assembly YES YES YES YES YES YES YES YES NO NO NO NO NO Is the terminal voltage of Capstan Motor supplied more than 4V Replace the Capstan Motor I...

Page 73: ... C Board 5V YES Is there a short circuit between cassette switch and GND on main P C Board Remove the short circuit part or Replace the main P C Board NO Check Mode switch location and syscon circuit Replace CST IN Switch YES NO YES NO NO Replace CST IN Switch NO NO Cassette will not eject Does the L D motor rotate in reverse Check L D Motor or Drive IC Replace lever Assembly Switch Does the Lever...

Page 74: ...embly F L Check the power of L D Motor Is the Holder Assembly Cassette assembled correctly Replace the Gear Rack F L Does the Gear Assembly Rack F L work Does the Opener Door work Does the Arm Assembly F L work Does the L D Motor work Does the Holder Assembly Cassette move the Arm Assembly F L Replace the Front Loading Mechanism Assembly YES YES YES YES NO NO NO YES NO YES NO YES NO C ...

Page 75: ...4 28 EXPLODED VIEWS 117 103 105 117 100 106 107 A21 114 113 112 110 115 A24 116 102 A23 032 A22 109 054 054A 1 Front Loading Mechanism Section ...

Page 76: ...29 401 402 001 008 011 031 079 017 032 024 406 020 021 028 019 018 029 030 026 A03 A04 A01 002 002A 025 027 022 003 004 006 007 010 405 014 015 009 409 013 023 016 405 012 402 OPTIONAL PART 2 Moving Mechanism Section 1 ...

Page 77: ...EXPLODED VIEWS 4 30 051 052 517 061 056 058 518 052A 055 060 410 070 069 076 032 077 068 064 066 065 067 A11 078 A12 3 Moving Mechanism Section 2 ...

Page 78: ...MEMO ...

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