1. Manuals
  2. Brands
  3. Sharp Manuals
  4. TV
  5. 21LF-90N
  6. Service manual

Sharp 21LF-90N Service Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
PAL
/ SECAM
B/G
ELECTRICAL SPECIFICATIONS ........................................................................................ 3
IMPORTANT SERVICING NOTES ...................................................................................... 4
CONTROLS & TERMINALS ................................................................................................ 5
PRINTED WIRING BOARD LAYOUT ................................................................................. 6
PARTS LISTING ................................................................................................................... 7
HOW TO UPDATE THE TECHNICAL INFORMATION ...................................................... 11
SHARP CORPORATION
SERVICE MANUAL
SYSTEM COLOUR TELEVISION
L/L', B/G, D/K
MODEL
In the interests of user safety (required by safety
regulations in some countries) the set should be re-
stored to its original condition and only parts identi-
cal to those specified should be used.
In order to service the model 21LF-90N, refer to
the
AK-44
(SE00AK44CHA00).
CONTENTS
1
Issued: 16
AK- 44
CHASSIS
21LF-90N
Chassis
Service
This document has been published to
be used for after sales service only.
21LF-90N
SE0021LF90N00
Feb. 2004
th
ES
Manual

Advertisement

Table of Contents
loading

Related Manuals for Sharp 21LF-90N

Summary of Contents for Sharp 21LF-90N

  • Page 1 In the interests of user safety (required by safety regulations in some countries) the set should be re- stored to its original condition and only parts identi- cal to those specified should be used. In order to service the model 21LF-90N, refer to AK-44 Chassis Service Manual (SE00AK44CHA00).
  • Page 2 21LF-90N SERVICE MANUAL UPDATE LOG SHEET Technical Report No. Application Cause / Solution Part No. Page No. Data /Serial No. Technical Bulletin No. Use this page to keep any special servicing information as Technical Report (Bulletin), Technical Information, etc. If only part number changes are required, just change part number directly the part number in the Parts Listing Section.
  • Page 3 21LF-90N ELECTRICAL SPECIFICATIONS •Picture Intermediate frequency •Power Input ....220V-240 Volts AC 50 Hz L’ ..........33.9MHz L, B/G, D/K ......38.9MHz •Power Consumption •Sound Carrier Trap Normal Operation (Method IEC60107) ....62 W L’ ..........40.4MHz Stand-by Operation .......... < 3 W L, D/K .........
  • Page 4 21LF-90N IMPORTANT SERVICING NOTES Only qualified service personnel are allowed to carry out maintenance and repair of this receiver. Servicing of High Voltage System and CRT It is important that the static charge is removed from the high voltage system when carrying out work on the receiver.
  • Page 5 21LF-90N CONTROLS & TERMINALS Speakers (left + right) = Power On / Off = Volume -/+ = Program -/+ MENU = Menu VIDEO = VCR AUDIO L = Audio left AUDIO R = Audio right MENU = Headphone 3,6 mm Ø...
  • Page 6 21LF-90N CHASSIS LAYOUT Mother Unit Headphone Unit CRT Unit...
  • Page 7 X100 30002852 XTAL REZ 455KHZ 30017634 21" CPT TUBE SAFE EW FREE REALFLAT X401 30001749 XTAL 4.433619 MHZ (AK15) 30028644 21 DEG COIL&EARTH CB. WO/UL FLAT SHARP X402 30015592 XTAL 3.579545 (WO/LOAD CAP) X403 30000074 CAP MKT 100NF 63V J...
  • Page 8 21LF-90N REF No. PARTS DESCRIPTION SN CODE EX CODE REF No. PARTS DESCRIPTION SN CODE EX CODE C100 30000352 CAP EL 100UF 16V M C738 30000371 CAP EL 22UF 50V M C201 30000400 CAP EL 47UF 50V M C801 30000094 CAP MKT SAFE 220NF 275V M AC...
  • Page 9 JK100 30027656 JACK RCA 1P RED SHARP (AK44) 30027134 SPEAKER 16R 4W F/R 50x120MM-21" SHARP 30027654 JACK RCA 1P YELLOW SHARP (AK44) 30028208 POWER CORD SAFE EURO 2.2M SHARP W/FILTER NOT1 30009849 CABL 1P/70 SIS 35000136 FUSE HOLDER TK79-A (GRAY) PL100 30001829 CONN HEADER 2P 2.5MM TOP WHT SD...
  • Page 10 SN CODE EX CODE ARTWORK 20141199 SCR.ASSY.2163 HP (2SP) 20143026 R/C 1548 SHARP (EKO2GRAY/I) (GRAY/S) 35000158 NUT C ZN BOTTOM M3 35000165 KNURL WASHER C ZNSY 3*6*04 (M3) 35000180 SCREW C ZN YSMB M3*6 35000181 SCREW C ZN YSMB M3*8 35000182 SCREW C ZN YSMB M3*10 35000224 SCREW C SK ZN YFMB 2.9*9.5...
  • Page 11 21LF-90N How to update the Technical Information appeared on this Service Manual 1. Web site: https://www.vestelservice.com 2. Select: Technical Support 3. Login: 101278 4. Password: SHPII278 By this access you can consult the latest schematic diagram or request the Parts Listing of a concrete Production Date / Serial Number.
  • Page 12 Technical information and Production: Vestel Electronik AS PRINTED BY: Think Ecology, please use Technical information re-issued: SHARP ELECTRONICA ESPAÑA S.A. Service Manual Group Engineering Dept. Polígono Industrial Can Sant Joan 08190 Sant Cugat del Vallès Barcelona...

  • Page 13: Table Of Contents

    BLOCK DIAGRAM ........................ 22 SERVICE MODE ADJUSTMENTS ..................23 HOTEL MODE FUNCTIONS ....................30 CIRCUIT DIAGRAMS ..................... 31 HOW TO UPDATE THE TECHNICAL INFORMATION ............41 SHARP CORPORATION This document has been published to be used for after sales service only.
  • Page 14 AK - 44 CHASSIS SERVICE MANUAL UPDATE LOG SHEET Technical Report No. Application Cause / Solution Part No. Page No. Data /Serial No. Technical Bulletin No. Use this page to keep any special servicing information as Technical Report (Bulletin), Technical Information, etc. If only part number changes are required, just change part number directly the part number in the Parts Listing Section.

  • Page 15: Table Of Contents

    AK - 44 CHASSIS TABLE OF CONTENTS SAFETY PRECAUTIONS ............................... 5 TV set switched off ..............................5 Measurements ............................... 5 PERI-TV SOCKET ................................5 SCART 1................................... 5 1. INTRODUCTION ................................. 6 CIRCUIT DESCRIPTIONS ............................. 6 2. SMALL SIGNAL PART WITH STV2248 ........................6 2.1 Vision IF amplifier ............................
  • Page 16 AK - 44 CHASSIS TDA1308 ................................21 SAW FILTERS ............................... 21 13. GENERAL BLOCK DIAGRAM of 11AK44 ........................22 14. SERVICE MENU ..............................23 14.1 Service Menu entrance ..........................23 14.2 Service Adjustments ........................... 23 14.3 Using Coloured Buttons ..........................24 14.3.1 AVL ...............................

  • Page 17: Safety Precautions

    AK - 44 CHASSIS SAFETY PRECAUTIONS The service of this TV set must be carried out by qualified persons only. Components marked with the warning symbol on the circuit diagram or on the Parts Listing, are critical for safety and must only be replaced with an identical component. - Power resistor and fused resistors must be mounted in an identical manner to the original component.

  • Page 18: Introduction

    AK - 44 CHASSIS 1. INTRODUCTION 11AK44 is a 90° chassis capable of driving 20"/21" tubes at the appropriate currents. The chassis is capable of operating in PAL, SECAM and NTSC standards. The sound system is capable of giving 4 watts RMS output into a load of 16 ohms.

  • Page 19: Chroma And Luminance Processing

    AK - 44 CHASSIS composed of an integrated VCO (12 MHz) that requires the chroma Reference frequency (4.43 MHz or 3.58 MHz crystal oscillator reference signal), a divider by 768, a line decoder, and a phase comparator. • PLL2: The second phase locked loop that controls the phase of the horizontal output (Compensation of horizontal deflection transistor storage time variation).

  • Page 20: Μ-Controller

    AK - 44 CHASSIS 2.9 µ-Controller The ST92195 is the micro-controller, which is required for a color TV receiver. ST92195D1 is the version with one page Teletext and ST92195D7 is the one with 7 page Teletext. The IC has the supply voltage of 5 V and they are mounted in PSDIP package with 56 pins.

  • Page 21: Video Path

    AK - 44 CHASSIS 2.10 Video Path The detected video signal is output from pins 18 of IC403, to sound traps Z403/404. The video is taken from the other side via the appropriate filter to Pin 18 of IC403. (1.2 p to p) Video to the Scart connectors is taken after R458 to Pin 19 of the Scart connector.

  • Page 22: Digital Tv Sound Processor Msp34X0

    AK - 44 CHASSIS (2). Enough margin is available to tune up to 863.25 MHz. Noise Typical Max. Gain Min. Typical Max. Low band: 5 dB 9 dB All channels: 38 dB 44 dB 52 dB Mid band: 9 dB Gain Taper (of-air channels): 8 dB High band: 6 dB...

  • Page 23: Video Output Amplifier Tda6107

    AK - 44 CHASSIS 7. VIDEO OUTPUT AMPLIFIER TDA6107JF/N3 The TDA6107JF includes three video output amplifiers and is intended to drive the three cathodes of a colour CRT directly. The device is contained in a plastic DIL-bent-SIL 9-pin medium power (DBS9MPF) package, and uses high- voltage DMOS technology.

  • Page 24: Standby Operation

    AK - 44 CHASSIS This Current Sense pin senses the voltage developed on the series resistor R806 inserted in the source of the power MOSFET. When I sense reaches 1V, the Driver output (pin 5) is disabled. This is known as the Over Current Protection function.

  • Page 25: Integrated Circuit Descriptions

    AK - 44 CHASSIS 9.1 B.C.L Circuit (Beam Current Limiter) Beam current limiting is employed to protect the circuitry in the receiver, the CRT and to prevent excessive X Ray radiation in fault conditions. The current drawn by the CRT is monitored by the current drawn through the winding of the fly-back transformer that produces the EHT for the CRT anode.

  • Page 26: St92195

    AK - 44 CHASSIS ST92195 The ST92195 is a member of the ST9+ family of micro-controllers, completely developed and produced by STMicroelectronics using a proprietary n-well HCMOS process. The nucleus of the ST92195 is the advanced Core, which includes the Central Processing Unit (CPU), the ALU, the Register File and the interrupt controller. The Core has independent memory and register buses to add to the efficiency of the code.

  • Page 27: Stv224X

    AK - 44 CHASSIS STV224X Video processor The STV2246/2247/2248 are fully bus controlled ICs for TV including PIF, SIF, luma, Chroma and deflection processing. Used with a vertical frame booster (TDA1771 or TDA8174 for 90° chassis, STV9306 for 110° chassis), they allow the design of multi-standard sets with very few external components and no manual adjustments.
  • Page 28 AK - 44 CHASSIS 8. Not connected 9. Not connected 10. Symmetrical IF output 1 11. Symmetrical IF output 2 Band switching table: Pin 3 Pin 4 Pin 5 Low band + 5 V Mid band + 5 V High band + 5 V General description of UV1316 The UV1316 tuner belongs to the UV 1300 family of tuners, which are designed to meet a wide range of applications.

  • Page 29: Tda7266/Tda7266L

    AK - 44 CHASSIS TDA7266/TDA7266L General Description of TDA7266L The TDA7266L is a mono bridge amplifier specially designed for TV and Portable Radio applications. Requires very few external components WIDE SUPPLY VOLTAGE RANGE (3-18 V) MINIMUM EXTERNAL COMPONENTS. – NO SVR CAPACITOR –...

  • Page 30: Tda8174

    AK - 44 CHASSIS TDA8174AW INDEPENDENT VERTICAL AMPLITUDE ADJUSTMENT. BUFFER STAGE. POWER AMPLIFIER. FLYBACK GENERATOR. THERMAL PROTECTION. INTERNAL REFERENCE VOLTAGE DECOUPLING. General Description TDA8174A and TDA8174AW are a monolithic integrated circuits. It is a full performance and very efficient vertical deflection circuit intended for direct drive of a TV picture tube in Color and B &...

  • Page 31: Mc44608

    AK - 44 CHASSIS MC44608 General description The MC44608 is a high performance voltage-mode controller designed for off–line converters. This high voltage circuit that integrates the start–up current source and the oscillator capacitor, requires few external components while offering a high flexibility and reliability. The device also features a very high efficiency stand–by management consisting of an effective Pulsed Mode operation.

  • Page 32: 24C08

    AK - 44 CHASSIS Furthermore, pilot levels and identification signals can be evaluated internally with subsequent switching between mono/ stereo/bilingual; no I2C interaction is necessary (Automatic Sound Selection). The MSP 34x0G can handle very high FM deviations even in conjunction with NICAM processing. This is especially important for the introduction of NICAM in China.

  • Page 33: Tda1308

    AK - 44 CHASSIS TDA1308 Features Wide temperature range Excellent power supply ripple rejection Low power consumption Short-circuit resistant High performance high signal-to-noise ratio low distortion Pinning, Pin Value 1. Output A (Voltage swing): Min: 0.75 V, Max: 4.25 V 2.

  • Page 34: Block Diagram

    AK - 44 CHASSIS 13. GENERAL BLOCK DIAGRAM of 11AK44...

  • Page 35: Service Mode Adjustments

    AK - 44 CHASSIS 14. SERVICE MENU 14.1 Service Menu entrance All system, geometry and white balance alignments are performed in Service Mode. Before starting the service mode alignments, make sure that all manual adjustments are done correctly. To enter the service mode: 1.
  • Page 36 AK - 44 CHASSIS Default Values Register Parameter Notes A51EFS13X191 A51ELD032X001 APR Threshold Factory Setting Brightness Factory Setting Contrast Factory Setting Colour Factory Setting Sharpness Factory Setting Hue Factory Setting Volume White Point Adjust for Red (RGB mode) WR-R WG-R White Point Adjust for Green (RGB mode) White Point Adjust for Blue (RGB mode)

  • Page 37: Using Coloured Buttons

    AK - 44 CHASSIS 14.3 Using Coloured Buttons By using the four coloured buttons on the remote control (24, 23, 13, 14) different features or adjust may be accessed. Figure 6. Coloured buttons Remote Control 14.3.1 AVL Press the RED button (23) to activate or deactivate the AVL (Automatic Volume Level, between different broadcast channels).

  • Page 38: Geometry Table

    AK - 44 CHASSIS 14.3.2.1 Geometry Table Default Values Register Param eter A51EFS13X191 A51ELD032X001 16:9 16:9 Vertical Size VSIZ Vertical Position VPO S VSCO Not used VCCO Not used HSIZ Not used Horizontal Position HPO S Not used HPIN Not used HCCO HTRP Not used...

  • Page 39: If Adjustment

    AK - 44 CHASSIS 14.3.4 IF Adjustment Select IF1, IF2, IF3 or IF4. When the blue button (14) is pressed the before selected IF register is automatically adjusted. 14.4 Auto Programming System Set Up 1. Description In case the TV set should be serviced, there is the possibility of returning the set with the A.P.S. (Auto Programming System) activated in order to make easy the first start up to the customer.

  • Page 40: Registers Details

    AK - 44 CHASSIS 15.2 Registers Details OP1 – Peripheral Options NOT USED 1, Display “AV-3” as “F-AV” 0, Display “AV-3” as “B-AV” 1, Turn back TV mode after the last AV (with AV key) 0, Turn back first AV mode after the last AV 1, SVHS is available in AV key stream 0, SVHS is NOT available in AV key stream 1, RGB is available in AV key stream...
  • Page 41 AK - 44 CHASSIS OP4 – TV Features 1, Headphone is available (for STEREO models) 0, Headphone is not available 1, Arabic/Persian is Available in Menu Languages (for A, D, E, F, and later) 0, Arabic/Persian is NOT Available in Menu Languages 1, Hebrew is Available in Menu Languages (for A, D, E, F, and later) 0, Hebrew is NOT Available in Menu Languages 1, Hotel Mode can be activated...

  • Page 42: Hotel Mode Functions

    AK - 44 CHASSIS 16. LANGUAGES GROUP 1 GROUP 2 German English Italian Polish Dutch Slovak French Hungarian Spanish Russian Portuguese Bulgarian Swedish Czech Norwegian Rumanian Finnish Croatian Dannish English Greek Turkish 17. HOTEL MODE FUNCTIONS The following procedure details how to set up the Hotel Mode Functions. 1.

  • Page 43: Circuit Diagrams

    AK - 44 CHASSIS 18. CIRCUIT DIAGRAMS 18.1 Schematic Diagram of µ-Controller & IF Circuits...
  • Page 44 AK - 44 CHASSIS 18.2 Schematic Diagram of Video Circuit...
  • Page 45 AK - 44 CHASSIS 18.2 Schematic Diagram of Video Circuit...
  • Page 46 AK - 44 CHASSIS 18.3 Schematic Diagram of SMPS Circuit...
  • Page 47 AK - 44 CHASSIS 18.3 Schematic Diagram of SMPS Circuit...
  • Page 48 AK - 44 CHASSIS 18.4 Schematic Diagram of Audio Circuit...
  • Page 49 AK - 44 CHASSIS 18.5 Schematic Diagram of Deflection Circuit...
  • Page 50 AK - 44 CHASSIS 18.6 Schematic Diagram of Scart & AV Front Circuits...
  • Page 51 AK - 44 CHASSIS 18.6 Schematic Diagram of Scart & AV Front Circuits...
  • Page 52 AK - 44 CHASSIS 18.7 Schematic Diagram of CRT Socket Circuit...

  • Page 53: How To Update The Technical Information

    AK - 44 CHASSIS 19. HOW TO UPDATE THE TECHNICAL INFORMATION 19.1 How to update the Technical Information appeared on this Service Manual (and relatives) 19.1.1. Web site: https://www.vestelservice.com 19.1.2. Select: Technical Support 19.1.3. Login: 101278 19.1.4. Password: SHPII278 By this access you can consult the latest schematic diagram or request the Parts Listing of a concrete Produc- tion Date / Serial Number.
  • Page 54 AK - 44 CHASSIS 19.4 Code Bar Label Information Product Code From the beginning of September.2002, the production month and year will be indicated inside the box as shown. Year Month Year Consecutive number Consecutive number Year Batch number It is the code that indicates Vestel internal identification Product code: number of the complete TV set.
  • Page 55 AK - 44 CHASSIS Notes:...
  • Page 56 Technical information and Production: Vestel Electronik AS PRINTED BY: Think Ecology, please use Technical information re-issued: SHARP ELECTRONICA ESPAÑA S.A. Service Manual Group Engineering Dept. Polígono Industrial Can Sant Joan 08190 Sant Cugat del Vallès Barcelona...

Table of Contents