Sharp 20U200 User Manual

1
20U200, 20U250
51U200, 51U250
51U500, 51U550
WARNING
The chassis in this receiver is partially hot. Use an isolation transformer between the line cord plug and power
receptacle, when servicing this chassis. To prevent electric shock, do not remove cover. No user – serviceable
parts inside. Refer servicing to qualified service personnel.
SERVICE MANUAL
S90i420U200//
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 identical to those specified should be used.
MODELS
20U200, 20U250
51U200, 51U250
51U500, 51U550
SHARP CORPORATION
COLOUR TELEVISION
Chassis No. UA-1
Page
CONTENTS
» SPECIFICATIONS................................................. 2
» IMPORTANT SERVICE NOTES ........................... 2
» ADJUSTMENT PRECAUTIONS ........................... 3
» UA1 HOTEL MODE APPLICATION .................... 18
» TROUBLE SHOOTING TABLE ........................... 19
» SOLID STATE DEVICE BASE DIAGRAM .......... 21
» CHASSIS LAYOUT.............................................. 22
» BLOCK DIAGRAM............................................... 24
» WAVEFORMS ..................................................... 30
» DESCRIPTION OF SCHEMATIC DIAGRAM ...... 31
» SCHEMATIC DIAGRAM
Ë
MAIN UNIT (20U200/250) ............................... 32
Ë
MAIN UNIT (51U200/250) ............................... 34
Ë
MAIN UNIT (51U500/550) ............................... 36
Page
Ë
CRT UNIT ........................................................ 38
Ë
HEADPHONE UNIT......................................... 39
Ë
NICAM UNIT .................................................... 40
» PRINTED WIRING BOARD ASSEMBLIES......... 41
» REPLACEMENT PARTS LIST
Ë
ELECTRICAL PARTS
MAIN UNIT ...................................................... 46
CRT UNIT ........................................................ 51
HEADPHONE UNIT......................................... 51
NICAM/IGR UNIT ............................................ 51
Ë
SUPPLIED ACCESSORIES ............................ 53
Ë
PACKING PARTS ............................................ 53
Ë
CABINET PARTS............................................. 53
FEATURE
Ë
Favorite Channel
Ë
Full Auto Search System
Ë
100 CH Program Memory
Ë
CATV (Hyper Band) Ready
Ë
AVL (Sound Keeper) Function
Ë
High Contrast Picture (Black Stretch Circuit)
Ë
ON Timer/Sleep Timer/Reminder Timer
Ë
Blue Back Noise Mute
Ë
Front AV In and Rear AV In/Out Terminals
Ë
Rear Sub-Woofer Terminal
Ë
Front Headphone Jack
Ë
Colour-Comb Filter (NTSC AV In)
Ë
Hotel Mode
Ë
English Language OSD
Ë
Low Power Consumption
Ë
AV Stereo (20U200/250, 51U200/250)
Ë
NICAM/IGR Stereo Sound Output (51U500/550)
20U200 51U200/500
20U250 51U250/550

Sharp 20U200 Specifications

General

Brand	Sharp
Model	20U200
Category	TV
Language	English

Summary

SPECIFICATIONS

IMPORTANT SERVICE NOTES

SERVICE OF HIGH VOLTAGE SYSTEM AND PICTURE TUBE

Safety procedures for servicing high voltage systems and picture tubes.

X-RAY PRECAUTIONS

Guidelines to prevent hazardous X-ray radiation during servicing.

BEFORE RETURNING THE RECEIVER

ADJUSTMENT PRECAUTIONS

Setting the service mode by the microprocessor

Procedure for entering and utilizing the microprocessor-controlled service mode.

Factory Presetting

PIF ADJUSTMENT

Tuner IFT (PRESET) Adjustment

Procedure for adjusting the Tuner IFT using presets.

RF-AGC TAKE OVER POINT ADJUSTMENT

Steps for adjusting the RF-AGC take over point via I2C bus control.

PURITY ADJUSTMENT

Purity Adjustment Steps

Detailed steps for adjusting the CRT purity for optimal color display.

CONVERGENCE ADJUSTMENT

Convergence Adjustment Steps

Procedures for static and dynamic convergence adjustments on the CRT.

CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT

CRT CUTOFF (I2C BUS CONTROL)

Adjusting CRT cutoff characteristics using I2C bus control.

SUB-BRIGHTNESS ADJUSMENT (I2C BUS CONTROL)

Procedure for adjusting sub-brightness via I2C bus control.

WHITE BALANCE SERVICE MODE ADJ. (I2C BUS CONTROL)

Adjusting white balance using service mode and I2C bus control.

Maximum beam check

HORIZONTAL, VERTICAL, DEFLECTION LOOP AND FOCUS ADJUSTMENT

V-SLOPE (I2C BUS CONTROL)

Adjusting vertical slope using I2C bus control.

V-SHIFT (I2C BUS CONTROL)

Adjusting vertical shift using I2C bus control.

V-AMP (I2C BUS CONTROL)

Adjusting vertical amplifier gain using I2C bus control.

S-CORRECTION (I2C BUS CONTROL)

H-SHIFT (50) (H - CENTER) (I2C BUS CONTROL)

FOCUS

PAL CHROMA ADJUSTMENT

PAL Chroma Adjustment Procedure

Steps for adjusting PAL chroma settings, including oscilloscope use.

NTSC CHROMA ADJUSTMENT

SUB-TINT (I2C BUS CONTROL)

Adjusting sub-tint using I2C bus control with NTSC signals.

SIF (NICAM/IGR) ADJUSTMENT (51R500/550 ONLY)

VCO COIL T2300 Adjustment

Procedure for adjusting the VCO coil for SIF/NICAM/IGR signals.

UNIT BOARD ADJUSTMENT

PROTECTOR OPERATION CHECKING

Protector Checking Procedures

Steps for checking various protector circuits within the television.

A/V INPUT AND OUTPUT CHECKING

A/V Input and Output Checks

Procedures for verifying video and audio input/output functionality.

HEADPHONE JACK CHECKING

HEADPHONE OUTPUT CHECKING

Verifying headphone output and speaker mute during headphone use.

MEMORY MAP

EEPROM Memory Map Details

Detailed table mapping EEPROM addresses to their functions and data.

HOTEL MODE APPLICATION NOTE

Hotel Mode Conditions and Usage

TROUBLE SHOOTING TABLE

Troubleshooting Flowcharts

Flowcharts to diagnose and resolve common TV issues like no raster or sound.

TROUBLE SHOOTING TABLE (Continued)

Troubleshooting Synchronization and Color Issues

Diagnosing problems with vertical/horizontal synchronization and color reproduction.

MODELS 20U200/250, 51U200/250 CHASSIS LAYOUT

MODELS 51U500/550 CHASSIS LAYOUT

Chassis Layout Diagram

MODELS 20U200/250, 51U200/250 BLOCK DIAGRAM-1

Main Unit Block Diagram 1

MODELS 51U500/550 BLOCK DIAGRAM

Main Unit Block Diagram

BLOCK DIAGRAM-2

CRT Unit and Headphone Unit Diagrams

BLOCK DIAGRAM-3

NICAM/IGR Unit Diagram

WAVEFORMS

Waveform Diagrams and Measurements

MODELS 20U200/250 SCHEMATIC DIAGRAM: MAIN Unit

MODELS 51U200/250 SCHEMATIC DIAGRAM: MAIN Unit

MODELS 51U500/550 SCHEMATIC DIAGRAM: MAIN Unit

Main Unit Schematic Diagram

SCHEMATIC DIAGRAM: CRT Unit

CRT Unit Schematic Diagrams

SCHEMATIC DIAGRAM: HEADPHONE Unit

Headphone Unit Schematic Diagram

MODELS 51U500/550 SCHEMATIC DIAGRAM: NICAM Unit

NICAM Unit Schematic Diagram

PWB-A: MAIN Unit (Component Side)

PWB-A Component Side Diagram

PWB-A: MAIN Unit (Chip Parts Side)

PWB-A Chip Parts Side Diagram

PARTS LIST

HOW TO ORDER REPLACEMENT PARTS

MAIN UNIT Parts List (Continued)

Continuation of the parts list for the Main Unit, including miscellaneous parts.

TRANSISTORS

PICTURE TUBE

DIODES

CAPACITORS

PRINTED WIRING BOARD ASSEMBLIES (NOT REPLACEMENT ITEM)

PACKAGED CIRCUITS

COILS AND FILTERS

RESISTORS

HEADPHONE UNIT

NICAM UNIT (51U500/550)

RESISTORS

CABINET PARTS LOCATION

Cabinet Parts Location Diagrams