Sharp 20PL84 Service Manual

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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.

» ELECTRICAL SPECIFICATIONS ......................................................................................................... 1

» IMPORTANT SERVICE SAFETY PRECAUTION ................................................................................. 2

» LOCATION OF USER'S CONTROL ..................................................................................................... 4

» INSTALLATION AND SERVICE INSTRUCTIONS ................................................................................ 5

» CHASSIS LAYOUT ............................................................................................................................. 13

» BLOCK DIAGRAM .............................................................................................................................. 14

» DESCRIPTION OF SCHEMATIC DIAGRAMS & WAVEFORMS........................................................ 16

» SCHEMATIC DIAGRAMS ...................................................................................................................17

» PRINTED WIRING BOARD ASSEMBLIES ........................................................................................ 2 1

» REPLACEMENT PARTS LIST ............................................................................................................ 25

» PACKING OF THE SET ...................................................................................................................... 31

POWER INPUT ........................................ 110-220 V AC 50/60 Hz

POWER RATING .................................................................... 72 W

PICTURE SIZE .......................................... 1,194 cm

CONVERGENCE ............................................................. Magnetic

SWEEP DEFLECTION .................................................... Magnetic

FOCUS ............................................................... QPF Electrostatic

INTERMEDIATE FREQUENCIES

Picture IF Carrier Frequency ..................................... 45.75 MHz

Sound IF Carrier Frequency ...................................... 41.25 MHz

Color Sub-Carrier Frequency .................................... 42.17 MHz

AUDIO POWER

OUTPUT RATING ....................... 3.0 + 3.0 W (at 10% distortion)

SERVICE MANUAL

MODELS

CONTENTS

ELECTRICAL SPECIFICATIONS

SPEAKER

(185sq inch)

ANTENNA INPUT IMPEDANCE

TUNING RANGES

(Nominal)

SHARP CORPORATION

COLOR TELEVISION

Chassis No. GA-1

20PL84

SIZE ................................................................ 9 × 5 cm (Round)

VOICE COIL IMPEDANCE ........................... 32 ohm at 400 Hz

VHF/UHF ..................................................... 75 ohm Unbalanced

VHF-Channels ............................................................... 2 thru 13

UHF-Channels ............................................................ 14 thru 69

CATV Channels ........................................................... 1 thru 125

Specifications are subject to change without

prior notice.

20PL84

Page

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Summary of Contents for Sharp 20PL84

Page 1: Table Of Contents
20PL84 SERVICE MANUAL COLOR TELEVISION Chassis No. GA-1 20PL84 MODELS 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.
Page 2: Important Service Safety Precaution
20PL84 IMPORTANT SERVICE SAFETY PRECAUTION Ë Service work should be performed only by qualified service technicians who are thoroughly familiar with all safety checks and the servicing guidelines which follow: WARNING X-RADIATION AND HIGH VOLTAGE LIMITS 1. For continued safety, no modification of any circuit 1.
Page 3: Safety Notice
20PL84 IMPORTANT SERVICE SAFETY PRECAUTION (Continued) • Connect the resistor connection to all exposed metal BEFORE RETURNING THE RECEIVER parts having a return to the chassis (antenna, metal (Fire & Shock Hazard) cabinet, screw heads, knobs and control shafts, escutcheon and etc.) and measure the AC voltage Before returning the receiver to the user, perform drop across the resistor.
Page 4: Location Of User's Control
20PL84 LOCATION OF USER'S CONTROL Front Panel VIDEO/AUDIO TERMINALS (VIDEO/AUDIO terminals are also provided on the rear.) POWER Press → On. Press again → Off. CHANNEL UP/DOWN (') Selects next higher channel. (") Selects next lower channel. ON TIMER indicator.
Page 5: Installation And Service Instructions
20PL84 INSTALLATION AND SERVICE INSTRUCTIONS Note: (1) When performing any adjustments to resistor controls and transformers use non-metallic screwdrivers or TV alignment tools. (2) Before performing adjustments, the TV set must be on at least 15 minutes. HIGH VOLTAGE CHECK CIRCUIT PROTECTION The receiver is protected by a 3.15A fuse (F701),...
Page 6 20PL84 For adjustments of this model, the bus data is converted to various analog signals by the D/A converter circuit. Note: There are still a few analog adjustments in this series such as focus and master screen voltage. Follow the steps below whenever the service adjustment is required. See "Table-B" to determine, if serv- ice adjustments are required.
Page 7 20PL84 SERVICE MODE (1) In the Service Mode, Key is used to select the mode in the following oreder. AGC & WHITE POINT GEOMETRIC ADJ. ADJ. MODE MODE MODE OFFSET ADJ. MODE FEATURE OPTION OPTION ADJ. MODE MODE MODE AGC &...
Page 8: Speaker
20PL84 OFFSET ADJ. ADJ. MODE MODE ↓ ↓ Y-D TIME (TV) [ YD ] (DL-TV) ATTENUATE INPUT SIGNAL LEVEL (ATT) ↓ ↓ Y-D TIME (AV) [ YD ] (DL-AV) VCO FREE RUNNING FREQUENCY ADJ. (VCO) ↓ ↓ INITIAL/DEFAULT LANGUAGE (INIT) STEREO, SAP, DBX FILTER ADJ.
Page 9: Service Mode
20PL84 SERVICE MODE DATA SERVICE REMARK ADJUST ITEM POSITION RANGE INITIAL VALUE FIX/ADJ AGC TAKE OVER POINT 0~63 V-LIN VERTICAL SLOPE 0~63 V-AMP VERTICAL AMP 0~63 V-CENT VERTICAL SHIFT 0~63 V-ZOOM VERTICAL ZOOM 0~63 H-CENT HORIZONTAL SHIFT 0~63 H-SIZE EAST-WEST WIDTH...
Page 10 20PL84 DATA SERVICE REMARK ADJUST ITEM POSITION RANGE INITIAL VALUE FIX/ADJ FMWS FM WINDOW SELECTION 0(disable) or1(enable) SOUND MUTE BIT 0 (SM0) 0(disable) or1(enable) SOUND MUTE BIT 1 0(disable) or1(enable) AGC0 IF AGC SPEED BIT 0 0(disable) or1(enable) AGC1 IF AGC SPEED BIT 1...
Page 11: Service Adjustment
20PL84 Ë SERVICE ADJUSTMENT RF AGC Adjustment 1. Receive a good local channel. 2. Enter the service mode signal category and select the service adjustment "AGC". 3. Set the data value to point where no noise or beat appears. 4. Select another channel to confirm that no noise or beat appears.
Page 12 20PL84 CRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT No. Adjusting point Adjusting procedure/conditions Waveform and others CRT CUTOFF 1. Switch TV to VIDEO mode,BLUE BACK OFF, with ADJUSTMENT NO VIDEO signal. 3.5Vdc C BUS 2. Press R/C to set Picture Normal condition.
Page 13: Chassis Layout
20PL84 CHASSIS LAYOUT...
Page 14: Block Diagram
20PL84 BLOCK DIAGRAM-1...
Page 15 20PL84 MODEL 20PL84 BLOCK DIAGRAM...
Page 16: Description Of Schematic Diagram
20PL84 DESCRIPTION OF SCHEMATIC DIAGRAM WAVEFORM MEASUREMENT CONDITIONS: NOTES: 1. Photographs taken on a standard gated color bar 1. The unit of resistance "ohm" is omitted. (K=k Ω =1000 Ω , M=M Ω ) signal, the tint setting adjusted for proper color. The wave shapes at the red, green and blue cathodes of 2.
Page 17: Schematic Diagrams
20PL84 SCHEMATIC DIAGRAM: CRT Unit...
Page 18 20PL84 SCHEMATIC DIAGRAM: MAIN-1 Unit...
Page 19 20PL84...
Page 20 20PL84 SCHEMATIC DIAGRAM: MAIN-1 Unit...
Page 21: Printed Wiring Board Assemblies
20PL84 PRINTED WIRING BOARD ASSEMBLIES PWB-A: MAIN Unit (Wiring Side)
Page 22 20PL84 PWB-A: MAIN Unit (Chip Parts Side)
Page 23 20PL84 PWB-B: CRT Unit (Wiring Side) PWB-B: CRT Unit (Chip Parts Side)
Page 24 20PL84 PWB-E: MTS MODULE Unit (Wiring Side) PWB-E: MTS MODULE Unit (Chip Parts Side)
Page 25: Parts List
Q320 VS2SD601AR/-1Y X 2SD601AR in USA: Contact your nearest SHARP Parts Distributor to order. Q401 VS2SD601AR/-1Y X 2SD601AR For location of SHARP Parts Distributor, Please call Toll- Q601 VS2SC3207//-1+ X 2SC3207-AT Free; 1-800-BE-SHARP Q602 VS2SD2586//1E X 2SD2586 « MARK: SPARE PARTS-DELIVERY SECTION...
Page 26 20PL84 « Description « Description Ref. No. Part No. Code Ref. No. Part No. Code C533 VCQYTA1HM104J+ X 0.1 Mylar PWB-A: DUNTKA541WEL6 C601 VCQYTA1HM563J+ X 0.056 Mylar C602 VCEA0A1HW475M+ X 4.7 MAIN UNIT C603 VCEA0A1HW105M+ X 1 C604 VCEA0A2EW106M+ X 10...
Page 27 20PL84 Ref. No. Part No. « Description Code Ref. No. Part No. « Description Code R261 VRS-CY1JF223JY X 22k 1/16W M-Ox. PWB-A: DUNTKC290WEA4 R262 VRS-CY1JF560JY X 56 1/16W M-Ox. R263 VRS-CY1JF560JY X 56 1/16W M-Ox. MAIN UNIT R304 VRS-CY1JF221JY X 220 1/16W M-Ox.
Page 28: Crt Unit
20PL84 « Description « Description Ref. No. Part No. Code Ref. No. Part No. Code R1047 VRS-CY1JF332JY X 3.3k 1/16W M-Ox. PWB-A: DUNTKA541WEL6 R1050 VRS-CY1JF392JY X 3.9k 1/16W M-Ox. R1051 VRS-CY1JF683JY X 68k 1/16W M-Ox. MAIN UNIT R1066 VRS-CY1JF273JY X 27k 1/16W M-Ox.
Page 29 20PL84 « Description Ref. No. Part No. « Description Code Ref. No. Part No. Code C3032 VCEA0A1CW106M+ X 10 PWB-B: DUNTKA542WEA3 C3033 VCKYCY1HF103ZY X 0.01 Ceramic AA CRT UNIT C3034 VCEA0A1HW224M+ X 0.22 C3039 VCEA0A1CW227M+ X 220 RESISTORS CAPACITORS [M-Ox.··· Metal Oxide, M-Film ··· Metal Film] [EL.···...
Page 30: Packing Parts
20PL84 « Description « Description Ref. No. Part No. Code Ref. No. Part No. Code PACKING PARTS MISCELLANEOUS PARTS (NOT REPLACEMANT ITEM) SPAKCB305WJZZ X Packing case ACC701 QACCZA020WJPZ X AC Cord SPAKP0102GJZZ X Lamifoam SP301 VSP9050PB394A X speaker SPAKX0124GJZZ X Packing Foam...
Page 31: Packing Of The Set
20PL84 PACKING OF THE SET Polyethylene Bag Operation Manual Infrared R/C Unit Batteries Wrapping Paper Buffer Material FRONT Packing Case Use tape to fix top side of pack case. REAR Use 12 staples fix the packing case. MARK : Not Replacement Items.
Page 32 QRC0009-L August. 2004 Modify : SEMEX Design and Production Information SHARP ELECTRONICA MEXICO S. A. DE C. V. Design : SEM Quality & Reliability Control Center Production : SEMEX Blvd. SHARP No. 3510 Parque Industrial Rosarito...

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