Sharp 21F-PA18

21F-PD250 / 21F-PT220 / 21F-PA18 / 21F-PA18(B)
SERVICE MANUAL
COLOUR TELEVISION
Chassis No.GA-7
Blue Back Function
Aperture Control Circuit
Auto Fine Tuning
NTSC Colour Comb Filter
High Contrast Picture ( Black Stretch Circuit)
FEATURES
PAL-B/G, D/K
Frequency Synthesizer Tuner
Full Auto System
100-CH Program Memory
CATV (Hyper Band Ready)
Hotel Mode
White Temperature Select
Off Timer
Multi Languages OSD (English/Thai)
Rear AV IN / OUT Terminals
Child Lock
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 should be used.
CONTENTS
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.
WARNING
CHAPTER 1. SPECIFICATIONS
[1] SPECIFICATIONS .........................................
1-1
CHAPTER 2. IMPORTANT SERVICE NOTES
[1] IMPORTANT SERVICE NOTES ....................
2-1
CHAPTER 3. ADJUSTMENT PRECAUTIONS
[1] ADJUSTMENT PRECAUTIONS ....................
3-1
[2] ADJUSTMENT .............................................
3-14
CHAPTER 5. TROUBLE SHOOTING FLOWCHART
[1] TROUBLE SHOOTING FLOWCHART ..........
5-1
CHAPTER 6. SOLID STATE DEVICE BASE DIAGRAM
[1] SOLID STATE DEVICE BASE DIAGRAM.....
6-1
CHAPTER 7. CHASSIS LAYOUT
[1] CHASSIS LAYOUT .......................................
7-1
CHAPTER 9. DESCRIPTION OF SCHEMATIC DIA-
GRAM
[1] DESCRIPTION OF SCHEMATIC DIAGRAM...
9-1
CHAPTER 10. WAVEFORMS
[1] WAVEFORMS ...............................................
10-1
CHAPTER 11. SCHEMATIC DIAGRAM
[1] SCHEMATIC DIAGRAM : CRT UNIT............
11-1
[2] SCHEMATIC DIAGRAM : MAIN UNIT ..........
11-2
CHAPTER 12. PRINTED WIRING BOARD ASSEM-
BLIES
[1] PWB-A : MAIN UNIT .....................................
12-1
[2] PWB-B : CRT UNIT .......................................
12-3
Parts Guide
CHAPTER 4. MEMORY MAP
[1] MEMORY MAP...................................................
Front AV-IN Terminal (Model 21F-PT220)
4-1
CHAPTER 8. BLOCK DIAGRAM
[1] BLOCK DIAGRAM : MAIN UNIT...................
8-1
[2] BLOCK DIAGRAM : CRT UNIT ......................
8-9
SHARP MANUFACTURING (THAILAND) CO.,LTD.
21F-PT220
21F-PA18
21F-PA18(B)
21F-PD250
1st Edition
21F-PA18
21F-PA18(B)
21F-PD250
21F-PT220

Sharp 21F-PA18 Specifications

General

Brand	Sharp
Model	21F-PA18
Category	TV
Language	English

Summary

Chapter 1 Specifications

Specifications

Detailed technical specifications for the television models.

Chapter 2 Important Service Notes

Important Service Notes

Crucial safety and service guidelines for qualified personnel.

Chapter 3 Adjustment Precautions

Adjustment Precautions

Precautions and methods for adjusting the TV set using microprocessors.

Adjustment Item

List of adjustment items to be performed during service.

User Data in Service Mode

Details of user data established in service mode via remote control.

Shipping Setting and Checking

Default factory-set data for EEPROM and factory settings by model.

Adjustment Modes

Covers first, second, and fourth stage adjustment modes and settings.

Specific Adjustment Procedures

Detailed procedures for various technical adjustments.

Chapter 4 Memory Map

Memory Map

EEPROM check data list, detailing memory map and addresses.

EEPROM Check Data Lists

Comprehensive lists of EEPROM data for model configuration.

Chapter 5 Troubleshooting Flowchart

Troubleshooting Flowchart

Flowchart for diagnosing and troubleshooting TV issues.

Chapter 6 Solid State Device Base Diagram

Solid State Device Base Diagram

Base diagrams and pinouts for various semiconductor devices.

Chapter 7 Chassis Layout

Chassis Layout

Component layout diagram for main and CRT PCBs.

Chapter 8 Block Diagram

Block Diagram: Main Unit

Block diagram illustrating the main unit's functional blocks.

Block Diagram: CRT Unit

Block diagram illustrating the CRT unit's functional blocks.

Chapter 9 Schematic Diagram Description

Description of Schematic Diagram

Notes on safety, schematic conventions, and measurement conditions.

Chapter 10 Waveforms

Waveforms

Visual representations of expected waveforms at various test points.

Chapter 11 Schematic Diagram

Schematic Diagram: CRT Unit

Detailed schematic diagram for the CRT unit.

Schematic Diagram: Main Unit

Detailed schematic diagram for the main unit.

Chapter 12 Printed Wiring Board Assemblies

PWB-A: Main Component Side

Component layout for the main PWB (component side).

PWB-A: Main Chip Side

Component layout for the main PWB (chip side).

PWB-B: CRT Component Side

Component layout for the CRT PWB (component side).

PWB-B: CRT Chip Side

Component layout for the CRT PWB (chip side).

Sharp Parts Guide

Picture Tube Parts

Parts list for the picture tube and related components.

Printed Wiring Board Assemblies Parts

Parts list for printed wiring board assemblies.

Main Unit Parts

Parts list for components on the main unit.

CRT Unit Parts

Parts list for components on the CRT unit.

Miscellaneous Parts

List of miscellaneous parts not categorized elsewhere.

Supplied Accessories

List of accessories supplied with the product.

Cabinet Parts

Parts list for the external cabinet components of different models.

Packing Parts

List of packing materials used for shipping the product.