Sharp 20D2-S User Manual

1
20D2-S/G
21D1-S/G
21D2-S/G
20D2-S/G
21D1-S/G
21D2-S/G
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
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
SHARP CORPORATION
COLOUR TELEVISION
Chassis No. GA-1
FEATURES
Ë
Multi 18 systems
Ë
Full Auto Channel Preset and Auto Channel Skip
Ë
100-CH Program Memory
Ë
CATV(Hyper Band) Ready
<Used Frequency Synthesizer Tuner>
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 & Rear AV-In/Out Terminals
(Front Priority)
Ë
Colour Comb Filter(NTSC only)
Ë
Headphone Terminal
Ë
Hotel Mode
Ë
Arabic/Chinese/English/French/Malay/Russian
6 Languages OSD
Ë
White Temperature Adjustment
S92Q420D2-S//
Page
CONTENTS
Page
» SPECIFICATIONS ............................................. 2
» IMPORTANT SERVICE NOTES ........................ 2
» ADJUSTMENT PRECAUTIONS ........................ 3
» MEMORY MAP ................................................ 12
» GA1 HOTEL MODE APPLICATION ................ 16
» TROUBLE SHOOTING TABLE ....................... 16
» WAVEFORMS .................................................. 19
» SOLID STATE DEVICE BASE DIAGRAM ....... 21
» CHASSIS LAYOUT .......................................... 22
» BLOCK DIAGRAM ........................................... 25
» DESCRIPTION OF SCHEMATIC DIAGRAM .. 31
» SCHEMATIC DIAGRAM
Ë
CRT UNIT..................................................... 32
Ë
HEADPHONE JACK UNIT ........................... 33
Ë
MAIN UNIT ................................................... 34
» PRINTED WIRING BOARD ASSEMBLIES ..... 40
» REPLACEMENT PARTS LIST
Ë
ELECTRICAL PARTS
MAIN UNIT ................................................... 45
CRT UNIT..................................................... 48
HEAD PHONE JACK UNIT .......................... 49
Ë
SUPPLIED ACCESSORIES ........................ 49
Ë
PACKING PARTS ......................................... 49
Ë
CABINET PARTS ......................................... 50
» PACKING OF THE SET ................................... 51
21D1-S/G
20D2-S/G
21D2-S/G

Sharp 20D2-S Specifications

General

Brand	Sharp
Model	20D2-S
Category	TV
Language	English

Summary

Colour Television Chassis GA-1

Critical Safety Warning

Provides essential safety precautions for servicing the television chassis.

Technical Specifications

Important Service Notes and Precautions

Provides crucial notes and precautions for safe and correct servicing procedures.

High Voltage and Picture Tube Servicing Safety

Details safety measures for working on high voltage systems and picture tubes.

X-Ray Radiation Safety Precautions

Advises on precautions to minimize X-ray radiation exposure during servicing.

Pre-Return Safety Checks

Outlines essential safety checks to perform before returning the receiver to the user.

General Adjustment Precautions

Entering Service Mode via Microprocessor

Step-by-step guide on how to access the service mode using microprocessor controls.

Factory Presetting Procedure

Details the procedure for factory presetting when using a new EEPROM or initial setup.

Initial Power-On Service Mode Requirement

Explains the requirement to enter service mode before the first power-on for chassis assembly.

Video Delay and Offset Adjustments

Video Delay and Offset Adjustments

Covers adjustments for Y-Delay and Offset settings, crucial for picture timing and positioning.

IC and Miscellaneous Option Adjustments

Details adjustments for IC options and miscellaneous settings affecting system behaviour.

EEPROM Item Settings and Initialization

Basic EEPROM Settings

Configuration settings for basic functions like scan disable, sharpness, and volume.

Advanced EEPROM Settings

Settings for more complex functions like white balance, languages, and TV system.

EEPROM Adjustment Notes

Provides essential notes and guidelines for correctly adjusting EEPROM parameters.

Initial Setting and Tuning Data Storage

Factory Shipping Settings and Checks

Details the default settings stored in the EEPROM for factory shipping and verification.

PIF Adjustment Procedures

Tuner IFT (Preset) Adjustment

Procedure for adjusting the Tuner IFT for proper signal reception and preset tuning.

RF-AGC Take Over Point Adjustment

Covers the adjustment of the RF-AGC take-over point for optimal signal handling.

CRT Purity Adjustment

Purity Adjustment Procedure

Detailed steps for adjusting the CRT purity for optimal colour convergence.

Purity Adjustment Warm-up Requirement

Specifies the necessary warm-up period and beam current for accurate purity adjustments.

Convergence Adjustment Procedures

Static Convergence Adjustment

Details the static convergence adjustments using 4-pole and 6-pole magnets.

Dynamic Convergence Adjustment

Explains the dynamic convergence adjustments required for screen fringe alignment.

CRT Cutoff, Background, and Sub-Contrast Adjustment

CRT Cutoff Adjustment Procedure

Steps to adjust CRT cutoff for proper display of white and retrace lines.

Sub-Brightness Adjustment

Procedure for adjusting sub-brightness for optimal display darkness levels.

White Balance Service Mode Adjustment

Details on adjusting white balance using service mode for correct color temperature.

PAL Chroma Adjustment (Continued)

Sub-Colour Adjustment

Procedure to adjust sub-colour for proper PAL color bar display.

Sub-Colour Adjustment Preconditions

Specifies the required initial settings for COL-OP, COL-OS, COL-O3, COL-04 before sub-colour adjustment.

NTSC Chroma Adjustment

Sub-Tint Adjustment

Procedure to adjust sub-tint for correct NTSC color bar waveform display.

CRT Cutoff, Background, Sub-Contrast (Continued)

Maximum Beam Current Check

Procedure for checking the maximum beam current to ensure safe operation.

Horizontal and Vertical Deflection Loop Adjustment

Vertical Slope Adjustment

Adjustment for vertical slope to correct picture geometry distortions.

Vertical Shift Adjustment

Procedure to adjust vertical shift for centering the picture vertically.

Vertical Amplitude Adjustment

Horizontal Shift Adjustment

S-Correction Adjustment

Sub-Sharpness Adjustment

Focus Adjustment

Protector Operation Checking

Beam Protector Circuit Check

High Voltage Protector Circuit Check

Function Operation Checking (Video and Audio)

AV Input and Output Checking

Video and Audio Functionality Tests

Tests for contrast, colour, brightness, tint, sharpness, and white temp settings.

White Temperature Adjustment Options

Colour System Selection and Verification

Memory Map and EEPROM Data

Basic Memory Map Entries

Picture Geometry Memory Map Entries

White Balance Memory Map Entries

Audio and System Settings Memory Map

Power and Channel Skip Memory Map

Display and Delay Settings Memory Map

Colour and Sharpness Offset Memory Map

Tuning Frequency Memory Map Entries

Troubleshooting Table

No Raster Troubleshooting

Diagnostic steps for identifying and resolving issues when no raster is displayed.

Troubleshooting Table (Continued)

No Picture, No Sound Troubleshooting

Diagnostic steps for issues where both picture and sound are absent.

No Specific Colour Troubleshooting

Diagnostic steps for when no specific colour is displayed or colour is incorrect.

Synchronization Issues Troubleshooting

Diagnostic steps for problems with vertical or horizontal synchronization.

PAL/SECAM Colour Synchronization Issues

Troubleshooting for colour synchronization problems in PAL and SECAM modes.

Vertical Amplifier and Linearity Issues

Troubleshooting for defective vertical amplifier and linearity problems.

No Sound Troubleshooting

Diagnostic steps for identifying and resolving issues where no sound is produced.

No Vertical Scan Troubleshooting

Diagnostic steps for problems where the vertical scan is not functioning.

Main Unit Block Diagram (20D2/21D2 Models)

Main Unit Block Diagram (21D1-S/G Model)

Schematic Diagram Description and Notes

Schematic Diagram Safety Notes

Safety precautions to be observed when referring to schematic diagrams.

Important Safety Notices for Schematics

Highlights critical parts marked 'A' for safety and performance in schematics.

Service Precaution for AC Mains Connections

Precaution for connecting an isolating transformer when working with AC mains voltage areas.

Schematic Diagram General Notes

Voltage Measurement Conditions

Waveform Measurement Conditions

Schematic Diagram: Main Unit (20D2-S/G)

Replacement Parts List

General Parts Replacement Notes

Notes on special safety characteristics of replacement parts and their impact.

Transistor Replacement Parts

Diode Replacement Parts

Picture Tube Replacement Parts

Printed Wiring Board Assemblies List

Tuner Replacement Parts

Integrated Circuits Replacement Parts

Packaged Circuits Replacement Parts