Page 1: Table Of Contents
Channel Skip Digital Automatic Tracking Control Automatic Playback Function n AHC (Automatic Head Cleaning System) Sharp Super Picture CONTENTS Page Page SPECIFICATIONS ..........2 TROUBLESHOOTING .
Page 2: Specifications
SPECIFICATIONS E OF THE PRODUCT Power Source: Power Consumption: Receiving Broadcast Standard: VHF; 1 A-S20 Receiving Channel: UHF; Sound; Receiving System: VHF/UHF; 75 ohm Unbalanced (DIN) Antenna Input Impedance: Video Signal: Input; output; 1 .O Vp-p/75 ohm (RCA) Audio Signal: Input;...
Page 3: Important Service Notes
IMPORTANT SERVICE NOTES Maintenance and repair of this receiver should be done by qualified service personnel only. SERVICING OF HIGH VOLTAGE SYSTEM AND PICTURE TUBE When servicing the high voltage system, remove static charge from it by connecting a IOk ohm Resistor in series with an insulated wire (such as a test probe) between picture tube dag and 2nd anode lead.
Page 4: Location Of User's Control
POWER/WAKE-UP TIMER indicator SHARP SUPER PICTURE button button (This function WIII create a clearer image dunng playback.) CHANNEL UP/DOWN buttons VOLUME UP/DOWN buttons I Rear1 INPUT INPUT OUTPUT VIDEO OUTPUT ANTENNA IN terminal This operation manual is for VT-3448X and VT-...
Page 5 LOCATION OF USER’S CONTROL (Continued) I Remote Control I Infrared Transmitter Window DISPLAY button Used to change the On Screen Dtsplay STANDBY/ON button - MI ITF hl attnn CHANNEL SELECT buttons-, Press + Mutes sound Press again + Restores sound to previous level. FLASHBACK button Returns to previously VOLUME UP/DOWN buttons...
Page 6: Disassembly And Reassembly
DISASSEMBLY AND REASSEMBLY...
Page 7 DISASSEMBLY AND REASSEMBLY (Continued)
Page 8 DISASSEMBLY AND REASSEMBLY (Continued) For servicing any of the components inside, disconnect the lead dressing holder. Position the main PWB unit upright as shown below and connect the leads for starting the services. Note: Fit the VCR unit the front cabinet with the front flap door tilted at 70-80”.
Page 9: Circuitry
ADJUSTMENT OF THE TV ELECTRICAL CIRCUITRY ADJUSTMENT PRECAUTIONS Place the set in the stand-by mode. Now the set will be in the service mode. There are three ways to get out of the service mode. Press the MENU key on the remote controller. A service mode item and its data appear in two lines at the lower left on the screen.
Page 10 Item-by-item control in the service mode (forced B/W) (drive forced center) SUB-BRIGHT Initial value 0 (E2PROM data resumed when any of the “1” thru CONTRAST (USER-CONTROL) (USER-CONTROL) BRIGHT CENTER (USER-CONTROL) COLOUR R-MONITOR SW 0 - > 1 (MONITOR OUT) Y-MUTE MUTE MODE CONTRAST (USER-CONTROL)
Page 11 Initial settings of EEPROM data Initial settings of adjustment items Item Variable range Initial setting R CUT OFF G CUT OFF B CUT OFF V-AMPLITUDE 50Hz V-AMPLITUDE 60Hz V-LINEARITY 50Hz V-LINEARITY 60Hz V-OUT PHASE 50Hz V-OUT PHASE 60Hz HORIZONTAL POSITION 50Hz HORIZONTAL POSITION 60HZ Y-SUB CONTRAST SUB-COLOUR...
Page 12 SERVICE ADJUSTMENT : TU201 (preset) I F-OUT 1 OOOp but with no signal input. Adjust the PLL data. 1 OkQ the tuner antenna. (RF sweep) probe with wave detector; see Fig.7) to the tun- Fig. 7 (This terminal must have the probe alone con- nected.) tact with the waveform.
Page 13 3. RF AGC CUT-IN ADJUSTMENT : R216 Oscilloscope TV Set 1. Receive the “E-12CH” (PAL COLOUR BAR) sig- Field strength: 57 +I dBpV (75 ohms open) Connect the oscilloscope to TP204, as shown at right. 3. Turn R216 to have the highest voltage. 4.
Page 14 in the set to warm it up for 30 minutes or longer. (over 700 PA for VT-5148X). - - - - in advance. Roughly adjust the static conver- gence. beam current to about 500 PA. (about 770 PA for Fig. A ADJUSTMENT Left Right...
Page 15 be done after the purity adjustment) STATIC CONVERGENCE - - . B ours. Fig. a Fig. b the blue and red colours. DYNAMIC CONVERGENCE _________________ 4 ____ i screen in the following steps. Fig. a : Drive the wedge at point “a” and - - - - - - - - - swing the deflection coil upward.
Page 16: R Cut Off
CRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT (1) 1 .CRT CUT-OFF (l*C bus data adjustment) the set) visible. Note : The data can be turned up and down with the above keys. G CUT OFF DOWN “5” KEY B CUT OFF UP G CUT OFF UP B CUT OFF DOWN “6”...
Page 17: V-Linearity 50Hz
CRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT (2) HORIZONTAL AND VERTICAL CIRCUIT ADJUSTMENT Put the set in the service mode. Turn up or down the data for this adjustment. V-AMP 50 Hz A) Select the V-AMP mode (V-AMP). Adjust the Note : The selected channels in parentheses have the V-LINEARITY - 50 Hz following signals.
Page 18: Sub-Colour
PAL CHROMA ADJUSTMENT (Use a 10 : 1 probe.) (TP855 for VT-5148X) Range: Sweep time: 20 psec/div. and red portions of the PAL colour bar be at the same level. See Fig. 8. To be at the same level When getting out of the SUB-COLOUR mode, Fig.
Page 19 AA/ INPUT AND OUTPUT CHECK tion audio) Make sure the output is as specified --_--------__I pedance. Make sure the output is as specified (2.6 Be sure that the audio output corresponds to the video output on the screen. jacks. change to the AV mode and make sure the exter- nal video and audio outputs are accordingly given.
Page 20 FUNCTION CHECK (1) (VIDEO AND AUDIO) TRAST. OUR. (There must be no colour at the MIN position.) key. Here are the normal settings. Contrast : MAX (60) : CENTER (0) Brightness : CENTER (0) Tint : CENTER (0) Sharpness : CENTER (0)
Page 21 FUNCTION CHECK (2) (VIDEO AND AUDIO) Note : When the NTSC 4.43 colour bar special sig- OUR SYSTEM key, select a mode other than nal is used in the AUTO mode, the colour sys- AUTO/PAL and make sure the colour system does tem does not work.
Page 22 in the service mode. place the set in the stand-by mode. El NVM 000 MODE 12 ADDRESS DATA Note: The above settings are required for the IClOOl coded RH-iX2978CEZZ.
Page 23: Precautions In Reassembling
PRECAUTIONS IN REASSEMBLING MOUNTING THE CASSETTE CONTROLLER Initial setting is indispensable before placing the cassette controller in the mechanism. The initial setting is made in two ways; electrical and mechanical. Electrical setting: Make a short-circuit between TP7701 and TP7702 then plug in the AC cord and be sure that the mechanism is back to its initial setting position (*l).
Page 24 FUNCTION OF MAJOR MECHANICAL PARTS (TOP VIEW) Automatic Head Cleaner Ass’y Drum Motor Take-up Pole Base Ass’y Pinch Roller Lever Ass’v Drum Ass’y Full Erase Head Supply Pole Reverse Guide Base Ass’y Tension Arm Ass’yu&m Idler Wheel Sup Main Supply Reel Loading Brake Ass’y Take-up...
Page 25 FUNCTION OF MAJOR MECHANICAL PARTS (BOTTOM VIEW) Take-up Loading Gear Limiter Clutch Pulley A&y Lever No. 1 Function Function Slow brake Gets in contact with the capstan D.D. motor Transmits the power of the capstan D.D. motor to linking to the master cam in the slow still mode, the reel disk via the drive idler.
Page 26: Adjustment, Replacementand
ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS Here we will describe a relatively simple service work in the We are sure that the easy-to-handle tools listed below would field, not referring to the more complicated repairs which be more than handy for periodical maintenance to keep the would require the use of special equipment and tools (drum machine in its original working condition.
Page 27 Remarks Jig Item Part No. Code Configuration This Jig is used with the tension gauge. Rotary transformer clearance adjusting jig. This screwdriver is used for adjusting the guide roller height. This is used to screw down resinmade parts: the specified torque is 5kg. This Jig is used for height adjustment of the reverse guide (for reverse guide height adjustment).
Page 28 Use the table as a guide to maintain the mechanical parts in good operating condition. Possible symptom encountered Remarks Abnormal rotation or significant Guide roller ass’y vibration requires replacement. Sup Guide Shaft Lateral noises Head occasion- ally blocked Clean tape contact part with Retaining guide the specified cleaning liquid.
Page 29 CASSETTE HOUSING CONTROL drive gear ASSEMBLY Drive angle of cassette control Removal mode. a) Remove the cassette housing installation screws 0. upward. Figure l-2. Notes: from the A/C head, FE (Full Erase) head, and the drum. sette housing control assembly and tools against the guide pin, drum, or the like there about.
Page 30 Notes: REPLACEMENT AND HEIGHT CHECKING @Take enough care not to deform the tension band during AND ADJUSTMENT OF REEL DISKS installation of the supply reel disk. Removal (Supply and Take-up reel disks) reel relay gear. Reassembly (Take-up reel disk) which makes unnecessary removal of the supply main brake and the take-up main brake.
Page 31 Check that the reel disk is lower than part A but higher than Adjustment part 6. If the height is not correct, readjust the reel disk height by changing the poly-slider washer under the reel disk. liquid, then recheck the torque. Note: Whenever replacing the reel disk, perform the height checking belt.
Page 32 CHECKING AND ADJUSTMENT OF TAKE- Adjustment UP TORQUE IN VIDEO SEARCH REWIND MODE liquid, then recheck the torque. Remove the cassette housing control assembly. belt. Make a short-circuit between TP7701 and TP7702, Notes: both located at the right on your side on the main PWB. Now plug in the AC cord.
Page 33 CHECKING THE VIDEO SEARCH REWIND BACK TENSION Remove the cassette housing control assembly. Make a short-circuit between TP7701 and TP7702, both located at the right on your side on the main PWB. Tension gauge Now plug in the AC cord. Pinch Checking mode.
Page 34 @Adjustable range of the tension pole ajuster. alignment with the line 1.3 mm left of the center line of the @Adjustable range of tension pole adjusting cam. sup guide shaft. Readjust as required in the following steps. Tension pole adjusting cam Sup guide shaft Figure l-1 8.
Page 35 Adjustment Checking the brake torque at the take-up side If the reading of the cassette torque meter is less than specified, move the tension spring hook toward A. If the reading of the cassette torque meter is more than Torque specified, move the tension spring hook toward B.
Page 36 REPLACEMENT OF A/C (Audio/Control) HEAD mark on the chassis, and temporarily tighten the screws @ Remove the cassette housing control assembly. and @ to allow the A/C head arm to smoothly move. Place the unit in the unloading mode, and unplug the power (Reference: Temporary tightening torque: 0.2 N.m as cord.
Page 37 ADJUSTMENT OF TAPE DRIVE TRAIN HEIGHT ADJUSTMENT OF REVERSE GUIDE Remove the cassette housing control assembly. [Height adjustment of reverse guide] Make a short-circuit between TP7703 and TP7704, both located at the right on your side on the main PWB. Now plug in the AC cord.
Page 38 Notes: a) Connect an oscilloscope to the audio output terminal. the X-position so that the PB CHROMA envelope becomes signal of 1 kHz, adjust the screws @and 0 to maximize maximum for easier rough adjustment of the tape drive train. the audio output, and adjust the screw @ to eliminate wrinkles from the tape at the retain guide flange.
Page 39 Reassembly response is obtained on the envelope waveform. sure not to allow the capstan shaft to hit the mechanism chassis, and attach it with the three screws. setscrew in the unloading mode. nector on the sensor PWB. that the envelope waveform does not change. Notes: a) In the X value adjustment mode (see the Electrical capstan D.D.
Page 40 ASSEMBLE THE MECHANISM’S PARTS REQUIRINGTHE PHASE MATCHING INTHE Double Actlon STEPS BELOW. Lever Ass’y Phase Matching Pomt @ assembly and the pinch drive cam (on the front of the mechanism chassis). chassis). nism chassis). motor assemblies (on the back of the mechanism chas- sis).
Page 41 point @ as shown below. mechanism chassis). points and the three release points. phase matching point @ as shown below. Drum Capstan points @ and @. Reel Pulley Phase-Matching (Bottom Side of mechanism chassis) Point Q Figure l-41. Cut Washer Insert Point 0 Cut Washer...
Page 42 REPLACEMENT OF LOADING M OTOR the mechanism chassis). Removal Remove 2 screws. shown below. E ring (XRESJ40-06000) Master Cam Note: See the figure below for the phase matching between the master cam and the cassette control drive gear. Figure l-44. Master Cam Replacement @Take out the old loading motor.
Page 43 ASSEMBLY OF CASSETTE HOUSING Figure l-46. Stamp mechanism cod\ Top surface should be free Figure l-47. Drive angle Drive gear R . F r a m e Figure l-48.
Page 44: Adjustment Of The Vcr
ADJUSTMENT OF THE VCR ELECTRICAL CIRCUITRY Notes: Before the adjustment: Electrical adjustments described here are often required after replacement of electronic components and mechanical parts such as video heads. Check that the mechanism and all electric components are in good working condition prior to the adjustments, otherwise adjustments can not be completed.
Page 45 Test points layout. Figure 2-2. Adjustment of PAL System LP still Adjustment of NTSC System EP still picture vertical sync picture vertical sync Measuring Monitor TV Measuring Monitor TV instrument instrument Mode Still picture playback Mode Still picture playback Input signal PAL LP self-recording tape Input signal Test point...
Page 46: Troubleshooting
‘This flowchart describes the outline of the mechanism’s operation, but does not give its details. CASSETTE INSERTION + STOP F mechanical timing Insert cassette. Cassette is ejected and loading motor stops. Made check Cam mark Start sensor lever turns on. Mode detection outside normal direction and master Mode detection inside...
Page 47 STOP -+ REWPLAY PLAY + STILL PLAY 3 VSR Press PLAY key. Pinch roller releasing Slow brake comes into p r e s s i n g contact with capstan motor. Cam switch is at STILL position. Idler Turn capstan motor in Loading motor stops.
Page 48 STOP + FF/REW STOP + CASSETTE EJECT Press FF/REW key. Press EJECT key. Loading motor turns in clockwise and master cam counterclockwise. Tape unloading Capstan motor turns in reverse direction. I ’ Cam switch is at UL Stop position. Stop loading motor. Are 4 supply reel Capstan motor turns pulses outputted ?
Page 49 M E C H A N I S M T R O U B L E S H O O T I N G Press FF key. Voltage supply Is voltage applied Is voltage applied system in trouble. to loading motor ? Voltage supply D o e s c a p s t a n N O Are 12V and 5V...
Page 50 insertion and ejection mode Go to 2. REC/ Is playback Is unusual sound heard during PLAY FAILURE function normal ? Replace Cassette control ass’y. routine. cassette control runninq ? Unusual sound heard with pinch roller Check pinch roller drive cam, pinch Go to 2.
Page 51 CASSETTE CONTROL TROUBLESHOOTING VCR POWER TROUBLESHOOTING FLOWCHART NO. l-l FLOWCHART NO. 1-2 The VCR is dead. (No power) A cassette tape is not taken in. Fix or replace the cassette housing. Does the start sensor cover become Check the start sensor cover. Is the fuse F701 alright in the power ND open when the cassette tape is Replace the fuse.
Page 52 LOADING MOTOR AND EJECT TROUBLESHOOTING SYSTEM CONTROL TROUBLESHOOTING FLOWCHART NO. l-5 FLOWCHART NO. 1-4 No power. A cassette tape fails to eject. Does the capstan motor start when Are serial clock pulse and TV data See FLOWCART NO. I-6 the EJECT button is pressed ? pulse applied to pins (66) and (67) of Check IClOOl and IC7701.
Page 53 CAPSTAN MOTOR TROUBLESHOOTING TAKE-UP REEL PULSE GENERATOR TROUBLESHOOTING FLOWCHARTNO. l-6 FLOWCHART NO. 1-7 The capstan motor fails to run. No reel sensor pulse appears. Is 5V at pin (1) of connector AC ? Check the PC5V line. Are there the take up/supply reel pulses at pins (4) and (5) of connector AM ?
Page 54 DRUM MOTOR TROUBLESHOOTING FLOWCHART NO. l-9 The drum motor fails to run. Check between the connector AD Is the voltage more than about 2.6V and pin (78) of IC7701, and between applied at pin (7) of connector AD ? the connector AD and pin (76) of Check the ATSV line.
Page 55 DRUM SERVO TROUBLESHOOTING FLOWCHART NO. l-l 1 Drum servo does not function. Is the reference voltage Check pins (89) and (90) In PB mode In REC mode Is there the durm PG Is there the reference signal at pin (86) of signal (V-sync.) at pin Is there the head Check the composite...
Page 56 CAPSTAN SERVO TROUBLESHOOTING FLOWCHART NO. 1-12 Capstan servo does not function. Only PB mode inoperative. Only REC mode inoperative. Are REC and/or PI3 mode inoperative ? Is there 16MHz oscillation at pins (38) and (39) of IC7701 ? Check X7701, C7705 and C7706.
Page 57 VCR RECORDING MODE (LUMINANCE) TROUBLESHOOTING VCR RECORDING MODE (CHROMA) TROUBLESHOOTING FLOWCHART NO. 1-13 FLOWCHART NO. 1-14 No record. Record is in black and white (E-E colour mode). Are there Y/C data and Are there Y/C data and clock signals at pins (17) clock signals at pins (17) Check data and clock...
Page 58 VCR PLAYBACK MODE (LUMINANCE) TROUBLESHOOTING VCR PLAYBACK MODE (CHROMA) TROUBLESHOOTING FLOWCHART NO. 1-15 No playback. Are there Y/C data and Are there Y/C data and clock signals at pins (17) clock signals at pins (17) and (18) of IC2201 and (18) of IC2201 respectively when respectively when playback starts ?
Page 59 VCR SOUND TROUBLESHOOTING FLOWCHART NO. 1-17 No Sound. No E-E signal. No record. No playback. Check parts around the Is there an Audio signal at Is there an Audio audio inputs jack, and pin (40) of IC2201 ? signal at pin (42) of Is there “L”...
Page 60 TV TROOUBLESHOOTING TABLE KEY-IN TROUBLESHOOTING FLOWCHART NO. 2-2 FLOWCHART NO. 2-1 Set not operating Key-in input is not received. Is AC cord connected ? __) Connect AC cord. Is the key switch in good contact ? Check the switch contact. Is AC applied to line Check ICI001 (iX2978CE) and Is there short-circuit in the key input ?
Page 61 TV TROUBLESHOOTING TABLE Circuit to be checked: FLOWCHART NO. 2-4 FLOWCHART NO. 2-5 NO PICTURE, NO SOUND control Does the noise level increase at max, Brightness, and Sound Control ? Contrast, Picture noise Noise increases but decrease but sound Replace the Fuse no signal is received.
Page 62 FLOWCHART NO. 2-6 FLOWCHART NO. 2-7 NO VERTICAL SCAN NO SOUND Vertical freq check Check IC301, IF Circuit : Does waveform appear Check IC301 and Normal Pin (53) of IC801 adjacent parts. at pin (3) of IC351 ? check. Check Check speaker.
Page 63 Circuits to be checked: Circuits to be checked: FLOWCHART NO. 2-11 FLOWCHART NO. 2-10 NO SPECIFIC COLOUR (PAL) NO SPECIFIC COLOUR (NTSC) Specific colours are not produced in Specific colours are not produced in , _ _ _ _ _ _ - - - _ - - _ _ - - -, Is there a chroma signal Is there a chroma signal Check IF Circuit and:...
Page 65: Chassis Layout
CHASSIS LAYOUT C H I L D L O C K VI DE0 UNIT POWER SW. I C7702 S T A R T S E N S O R E N D SEN V I D E O I N A U D I O I N V I D E O O U T A U D I O O U T...
Page 67: Block Diagram Of Tv Section
BLOCK DIAGRAM OF TV SECTION TO VCR SECT MAIN T O V C R S T A N D SECTION - B Y D O W N U P SYNC E - I N MUTE (LB DIG DIG B - I N AUDIO I N OUT OUT OUT E-IN ;@+-(E-IN\...
Page 68 P - F A I L K I L L K I L L SYNC V C R PE _ _ _ V C R VIDEO V C R REC V C R REC VIDEO V C R SECTION P/S-IF V - I N ) A - I N V - I N A - O U T V - O U T...
Page 69 BLOCK DIAGRAM OF TV SECTION PROTECT PHOTO COUPLER S W O N / O F F ERROR DETECT PHOTO COUPLER O N - T I M T O PWB-A ERROR DETECT P O W E R TRANS 0,,2 I----...
Page 70 R&VCR-KEY U&T TO PW’B-A V-OUTPUT POWER CONTROL - - - -...
Page 71: Description Of Tv Section
DESCRIPTION OF TV SECTION SCHEMATIC DIAGRAM SAFETY NOTE: BEFORE REPLACEING PARTS. REGARDED AS POTENTIAL SHOCK HAZARDS WHEN THE CHASSIS IS OPERATING. IMPORTANT SAFETY NOTICE: BE SURE TO USE GENUINE PARTS FOR SECURING THE SAFETY AND RELIABILITY OF THE SET. PARTS MARKED WITH “&’ ( ) ARE IMPORTANT FOR MAINTAINING THE SAFETY OF THE SET.
Page 72 SOLID STATE DEVICE BASE DIAGRAM T O P V I E W S I D E V I E W COLLECTOR COLLECTOR EMITTER...
Page 73 WAVEFORMS (VT-3448X) AC: 0.7Vp-p AC: O.SVp-p AC : 2.7Vp-p AC: 2.8Vp-p AC: 1 .OVp-p DC: 1.7V DC: 1.8V DC: 1.2V DC: 1.2V DC: 4.8V AC: 1.8Vp-p AC: l .Wp-p AC: 47Vp-p AC: 14OVp-p AC: 3.OVp-p DC: 1.2V DC: OV DC: OV...
Page 74 WAVEFORMS (VT-51 48X) AC: 0.7Vp-p AC: O.SVp-p AC: 2.7Vp-p AC: 1 .OVp-p AC: 2.8Vp-p DC: 1.7V DC: 1.8V DC: 4.8V DC: 1.2V DC: 1.2V AC: 47Vp-p AC: 122Vp-p DC: 2V DC: OV AC: 103OVp-p DC: OV...
Page 75 MODEL VT-3448X SCHEMATIC DIAGRAM OF TV SECTION: T O F.B.T...
Page 76 T O PWB-E V C R SECTION 2 SI...
Page 77 MODEL VT-3448X SCHEMATIC DIAGRAM OF TV SECTION:...
Page 78 DOWER, POWER SW, VCR-KEY and R/C Unit R&VCR-KEY UNIT TO PWB-A...
Page 79 MODEL VT-5148X SCHEMATIC DIAGRAM OF TV SECTION T O PWB-A T O F.B.T...
Page 80 MAIN and CRT Socket Unit TO PWB-E SECTION i - - - - - - - - - - - - - - - - - - J...
Page 81 MODEL VT-5148X SCHEMATIC DIAGRAM OF TV SECTION: POWER/V&H-OUT UNIT TO PWB-A TO PW6-A...
Page 82 POWER, POWER SW, VCR-KEY and R/C Unit TO PWB-A POWER-SW UNIT...
Page 83 A N T...
Page 84 Infrared Remote Control Unit...
Page 85: Block Diagram Of Vcr Section
BLOCK DIAGRAM OF VCR SECTION n OVERALL BLOCK DIAGRAM I - - I I I VIDEO INWT AUDIO YLECT S W . l - - - -...
Page 86 AUDIO SERVO PROCESS SYSTEM CoNfRoLLER CAPSTAN FG...
Page 87 BLOCK DIAGRAM OF VCR SECTION A T 5V V-SYNC SEP. SERVO/SYSTEM CONTOROLLER - - - - - - -...
Page 88 P A L GocniI - - - - - - - - - - - - - - - - - - - - - - - - - - - - MOTOR UUf l - - - - - - - - _ _ _ _ - - - - - _ _ _ - - - - - - _ _ _ _ I...
Page 89 DIAGRAM OF VCR SECTION BLOCK SYSTEM CONTROL BLOCK DIAGRAM...
Page 90 SERVO & SYSTEM CONTROLLER r - - - - - - - - - - - - 1 --- ------ -- TAKE REEL SENSOR ,...
Page 91 AUDIO BLOCK DIAGRAM HEAD AUDIO I BIAS FRTER HEAD SW. PC 9v...
Page 92 AUDIO MUTE04 ( F R O M PIN% O F IC77Ol) B I A S CTL 0-O (FROM PIN49 OF IC770 I)
Page 93 BLOCK DIAGRAM OF VCR SECTION n VIDEO SIGNAL FLOW BLOCK DIAGRAM...
Page 94 S I G N A L V C R...
Page 95: Description Of Vcr Section
DESCRIPTION OF VCR SECTION SCHEMATIC DIAGRAM POTENTIAL SHOCK HAZARDS WHEN THE CHASSIS IS OPERATING. NOTES: parentheses are the ones in the REC mode. VOLTAGE MEASUREMENT CONDITIONS: by VTVM, with AC 220 - 24OV, 50Hz supplied to unit and all controls are set to normal viewing picture unless otherwise noted.
Page 96 WAVEFORMS H : 4.43MHz (PAL) V : 500mVp-p V : BOOmVp-p v : 0.2vp-p V : 400mVp-p v : 1 .ovp-p v : 2.2vp-p v : l.OVp-p Pin (60) of IC2201 Pin (70) of IC2201 Pin (15) of IC2201 Pin (7) of IC2201 Pin (4) of lC2201 V : 4.6Vp-p V : 400mVp-p...
Page 97 S CH END SENSOR...
Page 98 L E D ORIVE L E D D R I V E L E D D R I V E L E D DRIVE SERVO CONTROLLER PC 5V GENERATOR...
Page 99 SCHEMATIC DIAGRAM OF VCR SECTION: VCR-2 Unit...
Page 100 D E L A Y L I N E T O T V...
Page 101: Printed Wiring Board Assemblies
PRINTED WIRING BOARD ASSEMBLIES I ', ', '- 1 '...
Page 102 (Wiring Side) (Wiring Side)
Page 104 nit (Wiring Side)
Page 106 (Chip Parts Side)
Page 107: Replacement Parts List
J Video Select Switch MARK Ir: SPARE PARTS-DELIVERY SECTION Ref. No. Part No. Description Code PRINTED WIRING BOARD ASSEMBLIES (NOT REPLACEMENT ITEM) MODEL VT-3448X TRANSISTORS R/C Receiver Unit MODEL VT-51 48X R/C Receiver Unit PICTURE TUBE MODEL VT-3448X MODEL VT-5148X...
Page 108 Description Code Ref. No. Part No. Part No. Description Code Ref. No. DIODES MAIN UNIT (Continued) J Zener Diode J Zener Diode J Zener Diode J Zener Diode J Zener Diode 6.2V J Zener Diode 3.3V J Zener D i o d e 6.2V J Start Sensor J End Sensor...
Page 109 Code Ref. No. Part No. Description Ref. No. Part No. Description Code MAIN UNIT (Continued) Ceramic PACKAGED CIRCUITS Ceramic Ceramic Ceramic Ceramic Ceramic COILS AND TRANSFORMERS Ceramic Ceramic Ceramic Ceramic Ceramic Mylar Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Filter Ceramic CONTROL CAPACITORS...
Page 110 Code Ref. No. Part No. Description Ref. No. Part No. Description Code 1 OV Electrolytic MAIN UNIT (Continued) Ceramic Ceramic Electrolytic Electrolytic 1 OV Electrolytic Electrolytic Ceramic Electrolytic Electrolytic Mylar Electrolytic Electrolytic Electrolytic Ceramic Mylar Electrolytic Electrolytic Electrolytic Ceramic Electrolytic Electrolytic Ceramic Ceramic...
Page 111 Description Code Ref. No. Part No. Ref. No. Part No. Description Code Ceramic Ceramic MAIN UNIT (Continued) Ceramic Ceramic Ceramic Electrolytic Ceramic Ceramic Ceramic Ceramic Ceramic Electrolytic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic Ceramic...
Page 112 Description Code Code Ref. No. Part No. Description Part No. Ref. No. Metal Oxide Metal Oxide MAIN UNIT (Continued) Fuse Resistor *AB Carbon Metal Oxide Ceramic Metal Oxide Ceramic Metal Oxide Metal Oxide Ceramic Metal Oxide Metal Oxide Ceramic Carbon .
Page 113 Ref. No. Ref. No. Part No. Description Code Part No. Description Code 1 l4W Fuse Resistc Metal Oxide MAIN UNIT (Continued) Metal Oxide Metal Oxide Carbon Carbon Metal Oxide Metal Oxide Metal Oxide Carbon Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Carbon...
Page 114 Description Code Ref. No. Description Code Ref. No. Part No. Part No. Metal Oxide Metal Oxide MAIN UNIT (Continued) Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide Metal Oxide...
Page 115 Description Code Ref. No. Part No. Description Ref. No. Part No. Code Metal Oxide AA Metal Oxide AA MAIN UNIT (Continued) Metal Oxide AA Metal Oxide AA Carbon Carbon Carbon Carbon Carbon Carbon Carbon ‘Carbon Carbon Carbon Carbon Carbon Metal Oxide AA Metal Oxide AA Metal Oxide AA Metal Oxide AA...
Page 116 Description Code Ref. No. Part No. Code Ref. No. Part No. Description MAIN UNIT (Continued) Metal Oxide AA Metal Oxide AA Metal Oxide AA Metal Oxide AA Carbon Metal Oxide AA Metal Oxide AA Carbon Metal Oxide AA J Plug 3-pin Metal Oxide AA Metal Oxide AA J Plug 2-pin TP7703/7704...
Page 117 Description Code Ref. No. Part No. Description Code Ref. No. Part No. POWER UNIT INTEGRATED CIRCUITS PACKAGED CIRCUIT Thermistor TRANSISTORS COIL AND TRANSFORMERS DIODES J Zener Diode 9.1V CAPACITORS J Zener Diode J Diode J Zener Diode 20V J Zener Diode 8.2V J Zener Diode 3.6V J Zener Diode 20V J Zener Diode 4.6V...
Page 118 Code Ref. No. Part No. Description Ref. No. Part No. Description Code Carbon POWER UNIT (Continued) Carbon Ceramic Carbon Ceramic Carbon Carbon Carbon 1 f4W Fuse Resistor AB Carbon Carbon 1 OOV Electrolytic AC Carbon Carbon Ceramic Carbon Carbon A 3.9k 1/2W Carbon Carbon Metal Oxide AC...
Page 119 Description Code Ref. No. Part No. Description Code Ref. No. Part No. POWER UNIT (Continued) Cement Metal Oxide AC Metal Oxide AC Metal Oxide AE Metal Oxide AA M e t a l F i l m A A J Heat Sink, for IC501 M e t a l F i l m A A J Heat Sink, for Q602 J Heat Sink, for IC701...
Page 120 Code Ref. No. Code Part No. Description Part No. Description Ref. No. 1 t8W Carbon CRT SOCKET UNIT TRANSISTORS MISCELLANEOUS PARTS DIODES COIL VP-C F68 1 KOOOO CAPACITORS POWER SWITCH UNIT DIODE COIL CAPACITOR SWITCH RESISTORS MISCELLANEOUS PARTS Metal Oxide Metal Oxide Metal Oxide...
Page 121 Description Code Ref. No. Part No. Ref. No. Part No. Description Code VCR-KEY UNIT SENSOR UNIT DIODE DIODES CAPACITOR RESISTORS CAPACITORS RESISTORS SWITCHES MISCELLANEOUS PARTS MISCELLANEOUS PARTS...
Page 122 Code Ref. No. Ref. No. Part No. Description Part No. Description Code V Light Guide MECHANISM CHASSIS PARTS V FFC for Drum Motor V Lead Wire for Loading Motor AD V Tension Band Ass’y V FFC for Audio/Control Head AF V Tension Arm Boss V Audio/Control Head PWB V Slow Brake Boss...
Page 123 MECHANISM CHASSIS PARTS...
Page 124 Description Code Ref. No. Code Ref. No. Part No. Part No. Description SCREWS, NUTS AND WASHERS CASSETTE HOUSING CONTROL PARTS V Screw V Cassette Housing V Screw Control Ass’y V Screw (for Audio/Control Head) V Frame-Left V Frame-Right V Screw, 2.6P+6S V Holder-Left (for Capstan Motor) V Holder-Right...
Page 125 CASSETTE HOUSING CONTROL PARTS...
Page 126 Code Ref. No. Part No. Description Code Description Ref. No. Part No. CABINET PARTS MODEL VT-3448X l - l Not Available Yoke Positioning...
Page 129 MODEL VT-5148X CABINET AND MECHANICAL PARTS - - -...
Page 131 Description Code Ref. No. Part No. Ref. No. Part No. Description Code CABINET PARTS MODEL VT-5148X Front Cabinet Ass’y Not Available l - l Button, Power Model Label...
Page 132 Description Code Ref. No. Part No. Description Code Ref. No. Part No. PACKING PARTS SUPPLIED ACCESSORIES (NOT REPLACEMENT ITEM) MODEL VT-3448X ACCESSORIES ACCESSORIES (NOT REPLACEMENT ITEM) MODEL VT-5148X...
Page 133: Of The Set
PACKING OF THE SET (VT-3448X) @Setting positions of the knobs LAST POWER ON POWER INITIAL CH POSITION SOUND VOLUME MAIN SWITCH (AUTO) COLOUR SYSTEM TAPE SPEED BLUE BACKGROUND WOUND-UP TIMER (RESET) VIDEO ADJUST SLEEP TIMER CLOCK...
Page 134 PACKING OF THE SET (VT-5148X) *Setting positions of the knobs INITIAL CH POSITION POWER LAST POWER ON SOUND VOLUME COLOUR SYSTEM MAIN SWITCH (AUTO) BLUE BACKGROUND TAPE SPEED WOUND-UP TIMER VIDEO ADJUST (RESET) SLEEP TIMER CLOCK R/C unit MARK * : Not replacement items.
Page 135 Memo...
Page 136 COPYRIGHT 0 1997 BY SHARP CORPORATION ALL RIGHTS RESERVED. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher.

This manual is also suitable for:

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Summary of Contents for Sharp VT-3448X

Page 1: Table Of Contents

Page 2: Specifications

Page 3: Important Service Notes

Page 4: Location Of User's Control

Page 6: Disassembly And Reassembly

Page 9: Circuitry

Page 16: R Cut Off

Page 17: V-Linearity 50Hz

Page 18: Sub-Colour

Page 23: Precautions In Reassembling

Page 26: Adjustment, Replacementand

Page 44: Adjustment Of The Vcr

Page 46: Troubleshooting

Page 65: Chassis Layout

Page 67: Block Diagram Of Tv Section

Page 71: Description Of Tv Section

Page 85: Block Diagram Of Vcr Section

Page 95: Description Of Vcr Section

Page 101: Printed Wiring Board Assemblies

Page 107: Replacement Parts List

Page 133: Of The Set

This manual is also suitable for:

Sharp VT-3448X Service Manual

Adjustment of the Vcr

Block Diagram of Vcr Section

Description of Vcr Section

Quick Links

Related Manuals for Sharp VT-3448X

Summary of Contents for Sharp VT-3448X

This manual is also suitable for:

Table of Contents