Sharp 20F640 Service Manual
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Sharp 20F640 Service Manual

Sharp 20F640 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
» SERVICE MODE ................................................................................................................................... 6
» ADJUSTMENT METHOD ..................................................................................................................... 7
» CHASSIS LAYOUT ............................................................................................................................. 11
» BLOCK DIAGRAM .............................................................................................................................. 12
» DESCRIPTION OF SCHEMATIC DIAGRAM ...................................................................................... 17
» WAVEFORMS ..................................................................................................................................... 18
» SCHEMATIC DIAGRAMS ................................................................................................................... 19
» PRINTED WIRING BOARD ASSEMBLIES ........................................................................................ 24
» REPLACEMENT PARTS LIST ............................................................................................................ 27
» PACKING OF THE SET ...................................................................................................................... 34
POWER INPUT ..................................................... AC 120 V, 60 Hz
POWER RATING .................................................................... 90W
PICTURE SIZE .......................................... 1,239 cm
CONVERGENCE ............................................................. Magnetic
SWEEP DEFLECTION .................................................... Magnetic
FOCUS ................................................................................. Uni-Bi
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 ........................................ 2.5 W(RMS) x 2pcs
SHARP CORPORATION
SERVICE MANUAL
MODELS
CONTENTS

ELECTRICAL SPECIFICATIONS

SPEAKER
SIZE ................................................................... 5 x 12 cm, 2pcs
2
(192sq inch)
VOICE COIL IMPEDANCE ............................ 16 ohm at 400 Hz
ANTENNA INPUT IMPEDANCE
VHF/UHF ..................................................... 75 ohm Unbalanced
TUNING RANGES
VHF-Channels ............................................................... 2 thru 13
UHF-Channels ............................................................ 14 thru 69
CATV Channels ........................................................... 1 thru 125
(Nominal)
Specifications are subject to change without
prior notice.
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
COLOR TELEVISION
Chassis No. GA-2
20F640
(EIA, Channel Plan U.S.A.)
Page
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Summary of Contents for Sharp 20F640

  • Page 1: Table Of Contents

    SERVICE MANUAL COLOR TELEVISION Chassis No. GA-2 20F640 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

    20F640 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 20F640 IMPORTANT SERVICE SAFETY PRECAUTION (Continued) BEFORE RETURNING THE RECEIVER • Connect the resistor connection to all exposed metal parts having a return to the chassis (antenna, metal (Fire & Shock Hazard) cabinet, screw heads, knobs and control shafts, escutcheon, etc.) and measure the AC voltage drop Before returning the receiver to the user, perform across the resistor.

  • Page 4: Location Of User's Control

    20F640 LOCATION OF USER'S CONTROL Front Panel POWER VIDEO IN 2 L-AUDIO-R Press → On. Press again → Off. SENSOR AREA FOR (INSIDE DOOR) REMOTE CONTROL MENU Press → Accesses MAIN MENU. Press again → Exits MAIN MENU. VOLUME UP/DOWN CHANNEL UP/DOWN (+) Increases sound.

  • Page 5: Installation And Service Instructions

    20F640 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...

  • Page 6: Service Mode

    20F640 SERVICE MODE Service Mode Overview 1. Service mode is entered by SERVICE key input or CH-UP +VOL-DOWN input during reset. 2. Service mode is cleared by entering SERVICE key or CH-UP +VOL-DOWN key command during service mode. 3. If key input port (SERVICE) input is LOW, then it is in service mode.

  • Page 7: Adjustment Method

    20F640 ADJUSTMENT METHOD Adjustment Mode Items Caution: to get into the service mode, one of the ways is press direct key for service items. the other ways is short the main chassis JA309 and JA402 There is three stage of Service Mode data...
  • Page 8 20F640 Ë SELF ADJUSTMENT H-VCO 1. When there is H-VCO self-adjustment key input for adjustment item H-VCO, self-adjustment is performed. 2. H-FREE(1chip) is set to 1. 3. H-OUT is set by intelligent monitor output. 4. IM input is set as TIM input.
  • Page 9 20F640 Setting Mode Items Second Stage Item Name Register Range Default VideoTone-Gain (TV) 1chip V-TONE 0 / 1 VideoTone-Gain (AV) 1chip V-TONE 0 / 1 VideoTone-Gain(YUV) 1chip V-TONE 0 / 1 ABCL 1chip ABCL 0 / 1 1chip BS-OFF 0 / 1...
  • Page 10 20F640 Option Mode Items Third Stage ITEM DEFAULT DEM0 Without DEMO With DEMO O02 DOWNLOAD Without V-CHIP OP With V-CHIP OP O03 V-CHIP Without V-CHIP With V-CHIP O04 SPEAKER Without SPEAKER With SPEAKER O05 FAO Without FAO With FAO O06 P.PREF Without P.PREF...

  • Page 11: Chassis Layout

    20F640 MODEL 20F640 CHASSIS LAYOUT...

  • Page 12: Block Diagram

    20F640 MODEL 20F640 BLOCK DIAGRAM: CRT Unit...
  • Page 13 20F640 MODEL 20F640 BLOCK DIAGRAM: MAIN Unit...
  • Page 14 20F640...
  • Page 15 20F640 MODEL 20F640 BLOCK DIAGRAM: MTS MODULE Unit...
  • Page 16 20F640...

  • Page 17: Description Of Schematic Diagram

    20F640 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. signal, the tint setting adjusted for proper color. The (K=k =1000 , M=M Ω...

  • Page 18: Waveforms

    20F640 WAVEFORMS 1 1.024 Vp-p 2 5.69 Vp-p 3 5.69 Vp-p 4 5.84 Vp-p 5 2.00 Vp-p 6 2.08 Vp-p Horiz.Rate Horiz.Rate Horiz.Rate Horiz.Rate Vert.Rate Vert.Rate 7 6.56 Vp-p 8 6.40 Vp-p 9 4.88 Vp-p 0 158 Vp-p q 1140 Vp-p w 48 Vp-p Horiz.Rate...

  • Page 19: Schematic Diagrams

    20F640 SCHEMATIC DIAGRAM: MAIN-1 Unit...
  • Page 20 20F640...
  • Page 21 20F640 SCHEMATIC DIAGRAM: MTS MODULE...
  • Page 22 20F640...
  • Page 23 20F640 SCHEMATIC DIAGRAM: CRT Unit...

  • Page 24: Printed Wiring Board Assemblies

    20F640 PRINTED WIRING BOARD ASSEMBLIES PWB-A: MAIN Unit (Wiring Side)
  • Page 25 20F640 PWB-A: MAIN Unit (Chip Parts Side)
  • Page 26 20F640 PWB-B: CRT Unit (Wiring Side) PWB-E: MTS MODULE Unit (Wiring Side) R3 0 8 1 Q3 0 0 7 R3 0 0 5 C3 0 0 8 C3 0 8 2 R3 0 3 6 RJ 7 RJ 2...

  • Page 27: Replacement Parts List

    TRANSISTORS Q201 VS2SC2735//1EY 2SC2735 in USA: Contact your nearest SHARP Parts Distributor to order. Q302 VS2SD601AR/-1Y 2SD601AR For location of SHARP Parts Distributor, Please call Toll- Q601 VS2SC2482//-1+ 2SC2482 Free; 1-800-BE-SHARP Q602 VS2SD2539//1E 2SD2539 « MARK: SPARE PARTS-DELIVERY SECTION Q603...
  • Page 28 20F640 « Description « Description Ref. No. Part No. Code Ref. No. Part No. Code C392 VCQYTA1HM103J+ X 0.01 Mylar PWB-A: DUNTKB989WEA0 C393 VCEA0A1EW108M+ X 1000 MAIN UNIT (Continued) C434 VCEA0A1CW106M+ X 10 C435 VCE9GA1CW106M+ X 10 DIODES C436 VCKYCY1HF103ZY X 0.01...
  • Page 29 20F640 « Description « Description Ref. No. Part No. Code Ref. No. Part No. Code RJ43 VRS-CY1JF000JY X 00 1/16W M-Ox. PWB-A: DUNTKB989WEA0 RJ47 VRS-CY1JF000JY X 00 1/16W M-Ox. MAIN UNIT RJ50 VRS-CY1JF000JY X 00 1/16W M-Ox. RJ51 VRS-CY1JF000JY X 00 1/16W M-Ox.
  • Page 30 20F640 « Description « Description Ref. No. Part No. Code Ref. No. Part No. Code R817 VRS-CY1JF473JY X 47k 1/16W M-Ox. PWB-A: DUNTKB989WEA0 R818 VRS-RG3AB151J+ X 150 M-Ox. R823 VRD-RA2BE101JY X 100 1/8W Carbon MAIN UNIT R824 VRD-RA2BE101JY X 100...
  • Page 31 20F640 « Description « Ref. No. Part No. Code Ref. No. Part No. Description Code Q854 VS2SC3789//2E 2SC3789 PWB-A: DUNTKB989WEA0 Q855 VS2SC3789//2E 2SC3789 MAIN UNIT Q894 VS2SA1015Y/1E+ 2SA1015Y FILTERS L851 VP-MK820K0000+ Peaking 82mH RESISTORS CAPACITORS [M-Ox.··· Metal Oxide, M-Film ··· Metal Film] [EL.···...
  • Page 32 20F640 « « Ref. No. Part No. Description Code Ref. No. Part No. Description Code R3033 VRS-CY1JF102JY 1/16W M-Ox. PWB-E: DUNTKB271WEA3 R3034 VRS-CY1JF182JY 1.8k 1/16W M-Ox. MTS MODULE Unit R3035 VRS-CY1JF223JY 1/16W M-Ox. R3036 VRS-CY1JF102JY 1/16W M-Ox. R3080 VRS-CY1JF101JY 1/16W M-Ox.
  • Page 33 20F640 « « Ref. No. Part No. Description Code Ref. No. Part No. Description Code SUPPLIED ACCESSORIES CABINET PARTS ACCESSORIES CCABAA323WEH7 Front Cabinet Ass’y — RRMCGA108WJSA Infrared R-C Unit — Front Cabinet — HBDGB3155CESA SHARP Badge TGAN-A216WJN1 WARRANTY CARD HDECQA119WJSA...

  • Page 34: Packing Of The Set

    20F640 PACKING OF THE SET...
  • Page 35 20F640...
  • Page 36 QRC0017-U March. 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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