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VC-TA350/TA351/351W
VC-TA352W/TA355/TA356

VIDEO CASSETTE RECORDER

SERVICE MANUAL

CONTENTS

Page

1. SPECIFICATIONS ................................................................................................................. 3
2. DISASSEMBLY AND REASSEMBLY ................................................................................... 4
3. FUNCTION OF MAJOR MECHANICAL PARTS ................................................................... 7
4. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS .................. 9
5. ELECTRICAL ADJUSTMENT ............................................................................................. 28
6. MECHANISM OPERATION FLOWCHART AND TROUBLESHOOTING GUIDE .............. 31
7. TROUBLESHOOTING ........................................................................................................ 37
8. BLOCK DIAGRAM ............................................................................................................... 48
9. SCHEMATIC DIAGRAM AND PWB FOIL PATTERN ......................................................... 56

10. REPLACEMENT PARTS LIST ............................................................................................ 68
11. EXPLODED VIEW ............................................................................................................... 75
12. PACKING OF THE SET ...................................................................................................... 79

SHARP CORPORATION

VC-TA352W Only

In the interests of user-safety (Required by safety regulations in some
countries) the set should be restored to its original condition and only
parts identical to those specified be used.

MODELS

VC-TA350
VC-TA351
VC-TA351W
VC-TA352W
VC-TA355
VC-TA356

S70E1VC-TA350

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2
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Summary of Contents for VC-TA350

Page 1: ...N FLOWCHART AND TROUBLESHOOTING GUIDE 31 7 TROUBLESHOOTING 37 8 BLOCK DIAGRAM 48 9 SCHEMATIC DIAGRAM AND PWB FOIL PATTERN 56 10 REPLACEMENT PARTS LIST 68 11 EXPLODED VIEW 75 12 PACKING OF THE SET 79 SHARP CORPORATION VC TA352W Only In the interests of user safety Required by safety regulations in some countries the set should be restored to its original condition and only parts identical to those ...

Page 2: ...ment of part with the mechanism and its PWB in position in the main frame 1 Start and end sensors Q701 and Q702 Insert the sensor s projection deep into the upper hole of the holder Referring to the PWB fix the sensors tight enough 2 Photocoupler IC902 Refer to the symbol on the PWB and the anode marking of the part 3 Cam switches A and B D708 and D709 Adjust the notch of the part to the white mar...

Page 3: ...Channel E21 C57 RF converter output signal UHF Channel E21 E69 Adjustable preset to E60 For A M B W version UHF Channel E21 E69 Adjustable preset to E39 For S K L version Power requirement AC110 240V 50 60Hz Power consumption Approx 13W at 240V 50Hz Operating temperature 5 C to 40 C Storage temperature 20 C to 55 C Weight Approx 2 8 kg Dimensions 360 mm W x 256 mm D x 92 mm H VIDEO Input 1 0 Vp p ...

Page 4: ... ANTENNA TERMINAL COVER MECHANISM MAIN PWB ASSEMBLY TOP CABINET FIX ANGLE MAIN FRAME TOP CABINET Remove 2 screws 1 FRONT PANEL Remove 2 screws 3 and 7 clips 4 OPERATION Remove 1 screw 6 PWB SHIELD ANGLE Remove 1 screws 7 with shield angle MECHANISM Remove 1 screw 8 2screws 0 MAIN PWB 2 screws q Remove 1screw w with antenna terminal cover Remove 1 screw e with top cabinet fix angle OPERATION PWB ...

Page 5: ...w 2 Remove the FFC cable AA AD AH 3 which con necting the PWB and the mechanism Take out vertically the mechanism so that it does not damage the adjacent parts 2 Removing the mechanism and cassette housing Remove 2 screws 4 fixing the cassette housing to the mechanism and remove the cassette housing MECHANISM CHASSIS 2 1 3 4 CASSETTE HOUSING MAIN PWB 2 2 DISASSEMBLING THE MECHANISM MAIN PWB ASSEMB...

Page 6: ...as to perform initial setting of mechanism execute the Step 1 of Installation of cassette housing After ascertain ing the return to the initial setting position 1 install the 2 3 CARES WHEN REASSEMBLING START SENSOR PARTS WHICH NEED PARTICULAR CARE When installing the mechanism chassis on the PWB unit take care so as to prevent deformation due to contact of mechanism chassis with REC TIP SW AE CON...

Page 7: ...ead 2 Supply pole base ass y 3 Tension arm ass y 4 Idler wheel ass y 5 Pinch drive lever ass y 6 Supply reel disk 7 Supply main brake ass y 8 Take up main brake ass y 9 Pinch drive cam 10 A C Head ass y 11 Reverse guide lever ass y 12 Casecon drive gear 13 Take up reel disk 14 Pinch roller lever ass y 15 Drum ass y 16 Loading motor 17 Drum motor 18 Take up pole base ass y ...

Page 8: ...52W TA355 TA356 FUNCTION OF MAJOR MECHANICAL PARTS BOTTOM VIEW 25 24 21 22 19 20 12 23 No Function No Function 19 Slow brake lever 20 Master cam 21 Capstan D D motor 22 Reel belt 23 Clutch lever 24 Limiter pulley ass y 25 Shifter ...

Page 9: ...cking and adjusting the reel disk height When fixing any part to the threaded hole using resin with screw use the jig Specified torque 5 kg This cassette torque meter is used for check ing and adjusting the torque of take up for measuring tape back tension These Jigs are used for checking and adjusting the torque of take up and supply reel disks Master Plane Jig and Reel Disk Height Adjusting Jig ...

Page 10: ...is mechanism does not need electric adjustment with variable resistor Check parts If any deviation is found clean or replace parts Maintained Parts Remarks 500 hrs 1000 hrs 1500 hrs 2000 hrs Possible symptom encountered Guide roller ass y Sup guide shaft Reverse guide Slant pole on pole base Full erase head A C head Upper and lower drum ass y Capstan D D motor Pinch roller Reel belt Tension band a...

Page 11: ...ng control and tool do not contact the guide pin or drum 5 After installing the cassette housing control once per form cassette loading operation TO RUN A TAPE WITHOUT THE CASSETTE HOUSING CONTROL ASSEMBLY 1 Remove the full surface panel 2 Short circuit TP801 3 Plug in the power cord 4 Turn off the power switch The pole bases move into U L position 5 Open the lid of a cassette tape by hand 6 Hold ...

Page 12: ... not adhere the brake surface 2 After reassembly check the video search rewind back tension see page 15 and check the brake torque see page 17 Height checking and adjustment Note 1 Set the master plane with due care so that it does not contact the drum 2 When putting the master plane shift the reverse guide a little in the loading direction Care must be taken since excessive shift results in damag...

Page 13: ...fter short circuiting TP801 provided at the center facing to the main PWB plug in the power cord Setting 1 Set a torque gauge to zero on the scale Place it on the take up reel disk 2 Press the FF button 3 To calculate the remaining capacity of the play back mode slowly rotate the supply reel disk and then shift it into the forward mode Checking 1 Turn the torque gauge slowly one rotation every 2 t...

Page 14: ... and turn it counterclockwise very slowly one rotation every 1 to 2 seconds and check that the torque is within the set value 14 0 3 9mN m 144 40gf cm Figure 4 11 Torque gauge Supply reel disk Note Surely put the torque gauge on the reel disk to measure If the torque gauge is raised accurate measurement is impossible Adjustment If the rewinding playback winding up torque is not within the setting ...

Page 15: ...G THE VIDEO SEARCH REWIND BACK TENSION Remove the cassette housing control assembly After short circuiting TP801 provided at the center facing to the main PWB plug in the power cord Checking 1 After pressing the play button press the rewind button and set the video search rewind mode 2 Place the torque gauge on the take up reel disk and turn it counterclockwise very slowly one rotation every 2 to ...

Page 16: ...nge left right CHECKING AND ADJUSTMENT OF RECORD PLAYBACK BACK TENSION Remove the cassette housing control assembly After short circuiting TP801 provided at the center facing to the main PWB plug in the power cord Setting 1 Turn off the power switch 2 Open the torque cassette meter and fix with tape 3 Set the cassette tape in loading state 4 Put the weight 500g on the cassette torque meter 5 Turn ...

Page 17: ...urn 2 sec in the CCW direction CW direction so that the reel disk and torque gauge pointer rotates at equal speed and make sure that the value is within the setting CCW direction 4 9 to 13 7mN m 50 to 140gf cm CW direc tion 3 9 to 10 8 mN m 40 to 110gf cm 2 Adjustmentofthebraketorqueatthesupplysideandthe take up side Unless the supply side brake torque or take up side brake torque is within the se...

Page 18: ...mbly 2 In unloading state unplug the power cord Removal 1 Remove the screws123 Azimuth screw Tilt screw 2 Unsolder the PWB fitted to the A C head Notes 1 When replacing never touch the head If you touched clean with the cleaning liquid 2 When removing the screw 3 take care so that the spring may out A C head PWB 2 Spring 1 Solder 10 8mm 10 8mm Azimuth screw Height screw Tilt screw A C head base Fi...

Page 19: ...8 mm using the reverse guide height adjustment jig in tape loading state Refer to Figure 4 28 a b Figure 4 29 3 Set the tape and check for tape crease near the reverse guide in the playback mode If crease is found turn the reverse guide adjustment nut to remove crease As for crease check refer to Figure 4 30 a b Figure 4 28 2 Rotate counterclockwise the reverse guide height ad justment nut 1 10 tu...

Page 20: ...lockwise so that tape crease appears once at the flange and then return the tilt screw so that the crease disappears 2 If there is tape crease Turn counterclockwise the tilt screw so that the tape crease disappears Reference If the tilt screw is turned clockwise crease appears at the lower flange Guide roller Weight of 500g Cassette Tape 2 Adjustment of A C head height and azimuth 1 Perform the in...

Page 21: ... check the flatness of envelope waveform and sound Notes When the A C head X value adjustment is performed be sure to perform at first X value rough adjustment refer to Page 20 3 2 Take up side Supply side Take up side Adjustment Supply side Supply side guide roller rotated in clockwise direction lowers guide roller to flatten envelope Take up side guide roller rotated in clockwise direction lower...

Page 22: ... D D DIRECT DRIVE MOTOR Remove the mechanism from the main PWB refer to Page 6 item 1 When removing the mechanism from the main PWB Removal Follow the order of indicated numbers 1 Remove the reel belt 1 2 Remove the slow brake lever 2 3 Remove the three screws 3 Capstan D D motor Capstan D D motor control PWB 3 1 Reel belt Figure 4 37 1 2 Slow Brake lever Reassembly 1 Taking care so that the capst...

Page 23: ...HE UPPER AND LOWER DRUM ASSEMBLY Replacement Perform in the numerical order 1 Remove the motor as stated in Page 22 D D motor replacement 2 Remove the drum earth brush ass y 2 3 Remove the drum base 3 from the upper and lower drum assembly 1 Cares when replacing the drum 1 Be careful so that the drum earth brush is not lost 2 Do not touch directly the drum surface 3 Fit gently the screwdriver to t...

Page 24: ... Action Lever Ass y 3Insert Open Lever Insert reverse guide lever ass y Align here 2 Insert pinch drive cam Pinch drive lever ass y Fit the pinch drive cam so that the notch of pinch drive cam aligns with the dent of pinch drive lever assembly Fit the pinch drive cam so that the notch of pinch drive lever assembly aligns with the half round notch of chassis Turn the reverse guide lever assembly co...

Page 25: ...nt 3 3 For the phase matching at the insert point 1 see the PHASE MATCHING point 2 as shown below 4 Finally fix the inserts 1 and 4 Capstan D D motor Drum Reel pulley Bottom side of mechanism chassis Sifter Phase Matching point 2 Insert point 1 Half round notch Shaft 1 Round mark Loading gear T Insert point 3 Insert point 4 Insert point 5 Release point 3 Phase matching point 1 Shaft 1 Shaft 1 Shaf...

Page 26: ...Replacement Remove the loading motor and install the replacement loading motor as shown below Figure 4 46 Figure 4 44 2 Wheninstallingthemastercam align the casecon drive gear round mark with the half round notch of master cam The loading motor pressing in must be less than 147 N 15 kgf Adjust the distance between motor and pulley to 10 2 mm E ring XRESJ30 06000 Master cam Fully turn clockwise Ful...

Page 27: ...ve Gear L and Drive Gear R ASSEMBLY OF CASSETTE HOUSING 1 Drive Gear and R Drive angle ass y Figure 4 47 MSPRT0381GEFJ Apply grease Apply grease Apply grease LANGF9592GEFW Top surface should be free from scratches or soil Drive angle Drive gear R Frame Figure 4 48 ...

Page 28: ...s can not be completed Instruments required Colour TV monitor Dual trace oscilloscope Alignment tape VROCPSV VROATSV Blank video cassette tape DC voltmeter Screwdriver for adjustment Servicing precautions WhentheIC710 E2 PROM hasbeenreplaced makethefollowingreprogramming Dependingonmodels theIC710 E2 PROM has been factory adjusted for it s memory function It s therefore necessary to reprogram the ...

Page 29: ...V broadcast or feed a video signal to the VIDEO IN jack See note 2 below 2 Set the tape speed in SP mode by using the remote control and record the signal on tape 3 Rewind and play the tape where signal was recorded in above step 4 Press the SLOW button on the remote control and playback the recorded portion in the slow mode 5 Make for a moment short cirucuit TP801 Be sure that all the fluorescent...

Page 30: ...h the button Measuring instrument Mode Cassette Colour TV monitor Playback still Self recorded tape SP mode See Note below 1 Control Tracking control buttons or Specification ADJUSTMENT OF NTSC SYSTEM FV False Vertical Sync OF STILL PICTURE 1 Play a cassette which was recorded by the unit in SP mode 2 Press the PAUSE STILL button to freeze the picture 3 Look at the monitor screen and adjust or TRA...

Page 31: ...LW FF STP 0 1 1 0 1 1 0 0 0 0 0 1 0 0 1 or 0 Loading motor turns in reverse direction and master cam counterclockwise CASSETTE INSERTION STOP Cassette inserting Full loading YES YES YES NO NO NO Unloading Loading motor starts in normal direction and master cam counter clockwise Does mechanism position sw come off within 2 5 sec Are start end sensors at low level before cassette insertion Insert ca...

Page 32: ...motor stops End Stop capstan motor NO YES Press STILL key Pinch roller releasing Idler swinging Pinch roller pressing Loading motor turns clockwise and master cam counterclockwise Turn capstan motor in reverse direction Turn loading motor counterclockwise Cam switch is at VSR position Set capstan motor to search speed Is take up reel sensor signal outputted Press REW key Release pinch roller Cam s...

Page 33: ...n motor Loading motor stops End Loading motor turns in clockwise and master cam counterclockwise 4 supply reel pulses outputted Does the take up reel pulse output two edges Capstan motor turns clockwise Loading motor turns clockwise Cam switch is at Eject position Loading motor stops Capstan motor stops Press EJECT key Tape unloading Cassette eject End Capstan motor turns clockwise Capstan motor t...

Page 34: ...supply system in trouble Does capstan motor turn in FF or REW direction Are idler wheel ass y and reel disk in mesh Is the pulse outputted from reel sensor The cassette tape is presumably damaged 2 REC PLAY FAILURE MODE RELEASE NO NO NO NO NO NO NO YES YES YES YES YES YES YES YES Is the master cam at PB position Does loading motor operate Modes changing smoothly through cam switch Loading motor co...

Page 35: ...supply reel disk in mesh Is supply reel disk winding torque normal Is pulse outputted from reel sensor Check main PWB YES YES YES YES YES NO NO NO NO NO YES YES NO NO YES Press REW key 4 i Unusual sound in cassette insertion and ejection mode Is unusal sound heard during cassette coutrol running Unusual sound heard with pinch roller lever going up or down Is unusual sound heard during loading unlo...

Page 36: ...rust gap found at reel disk Drive system out of contact with any part on main PWB Turn capstan motor by hand Unusual sound heard Check drive system s gears for damage Replace damaged gear with new one Reel disk Limiter pulley ass y Idler wheel ass y Check reel disk and main chassis And replace defective parts Adjust reel disk height Rearrange the parts on main PWB ...

Page 37: ...se sound Check D921 D922 D923 D924 D925 and D926 The Check D921 D922 D923 D924 D925 and D926 Replace where necessary NO FLOW CHART NO 4 POWER TROUBLESHOOTING 4 No power is turned on Does power control H signal at pin 4 of IC701 change from L to H level Check IC701 YES YES YES NO NO NO Does the base of Q951 change from about 5 0V to 4 5V Check IC701 and all the way up through to Q951 Is voltage of ...

Page 38: ...ES YES YES YES NO NO NO NO FLOW CHART NO 8 KEY CONTROL TROUBLESHOOTING 1 Does the key switch make good contact when the cassette tape is inserted Check switch contact Is there the function control voltage inputted at pins 96 97 and 98 of IC701 when the jog shuttle ring are activated Check peripheral circuit of pins 96 97 and 98 of IC701 and the jog shuttle ring Replace IC701 YES NO NO YES Key in i...

Page 39: ...l when the cassette tape is inserted Does the start sensor cover go to open when the cassette tape is inserted NO NO NO FLOW CHART NO 12 CASSETTE CONTROL TROUBLESHOOTING 2 A cassette tape is taken in but ejected at once Does the start sensor pulse at pin 79 of IC701 change from L to H level when the cassette tape is loaded Check line between start sensor and pin 79 of IC701 Does the end sensor pul...

Page 40: ...ector 1 6 2 7V Check line between the pin 92 of IC701 and pin 3 of AC connector Is the supply voltage of 12V 20V fed to pin 5 of AC connector YES Replace capstan motor Check MOTOR Vcc line and motor voltage selector circuit Q995 996 FLOW CHART NO 16 DRUM MOTOR TROUBLESHOOTING 2 The drum motor runs only for a few seconds Replace IC706 Check peripheral circuit of pins 4 5 and 6 of IC706 Is drum PG s...

Page 41: ... CAPSTAN SERVO TROUBLESHOOTING Capstan servo does not function Only PB mode inoperative YES NO Check 1 Check capstan motor unit and or replace Is there capstan AFC and APC at pins 31 and 33 of IC701 Replace A C head YES NO YES NO NO YES NO Is there capstan AFC signal at pin 31 of IC701 Replace IC701 NO Is there REC CTL signal output at pins 75 and 74 of IC701 Does PB CTL signal appear at pin 76 of...

Page 42: ...pin 52 of IC201 and pin 49 of IC701 YES YES YES YES Is there a picture signal outputted in the emitter of Q251 Check peripheral circuit of Q251 NO NO Is there Y C serial data and Y C clock signal applied to pins 63 and 62 of IC201 Check line between pins 63 62 of IC201 and pins 56 57 of IC701 Is the supply voltage of 5V OSD Vcc fed to pin 51 of IC701 Replace IC201 NO Check PC 5V line 1Line output ...

Page 43: ...L or NTSC mode E E mode is possible NO NO NO YES Is voltage of 5V applied to the chroma power terminal at pin 61 of IC201 Check peripheral circuit pin 61 of IC201 and Y C 5V line Is there chroma signal approx 156mVp p PAL mode or 298mVp p NTSC mode burst input in the pin 46 of IC201 Check line between pins 60 and 46 of IC201 C512 Is there chroma signal approx 197mVp p PAL mode or 375mVp p NTSC mod...

Page 44: ...the chroma power terminal at pin 61 of IC201 YES Check peripheral circuit of pins 61 of IC201 and Y C 5V line NO Is there chroma signal approx 156mVp p PAL mode or 298mVp p NTSC mode burst input in the pin 46 of IC201 YES NO Is there chroma signal approx 197mVp p PAL mode or 375mVp p NTSC mode burst input in the pin 58 of IC201 Check line between pins 58 and 35 of IC201 R505 C515 NO NO YES Is ther...

Page 45: ...f IC201 Is there a signal at pin 4 of IC201 YES YES No linear sound recording Is the supply voltage of 12V fed to pin 2 of T601 Check the AUDIO MUTE H line between pin 99 of IC651 and pin 21 of IC701 Replace IC201 Check PC 12V line NO YES YES Is there signal Bias at pin 5 of T601 Check the Bias oscillation circuit T601 Q602 Q603 and FE BIAS CTL line NO Is there signal Bias Audio sig at pin 6 of T6...

Page 46: ...al notation from the feature function Example ON and OFF are taken as 1 and 0 respectively JP39 JP38 JP37 JP36 JP35 JP34 JP33 JP32 JP31 JP30 JP29 JP28 JP27 JP26 JP25 JP24 JP23 JP22 JP21 JP20 0 0 1 1 0 1 1 0 0 0 0 0 0 0 0 0 1 0 0 0 3 6 0 0 8 2 Memory recording preset level reprogramming 1 Similarly to the above step 1 1 and 2 the same operate 2 Using the CHANNEL AND buttons select the right functio...

Page 47: ... CODE 1 2 0 0 0 JP27 DNR 0 0 0 JP26 POST CODE 0 0 0 JP25 SAT CTL 0 0 0 JP24 AV LINK 0 0 0 JP23 Hi Fi 0 0 0 JP22 SORT AUTO CLOCK 0 0 0 JP21 DECODER 0 0 0 JP20 DOLBY SURROUND 0 0 0 JP19 NICAM 1 0 0 0 JP18 NICAM 0 0 0 0 JP17 G CODE 1 0 0 1 JP16 G CODE 0 0 0 0 JP15 OEM 1 1 1 JP14 LP 0 1 1 JP13 FRONT AV 0 0 1 JP12 DUBLE SCART 0 0 0 JP11 NOT RF OUT 0 0 0 JP10 TUNER 2 1 1 1 JP 9 TUNER 1 1 1 1 JP 8 TUNER ...

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