Sharp 25MR15J Service Manual
Sharp 25MR15J Service Manual

Sharp 25MR15J Service Manual

Color television

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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
» SERVICE INSTRUCTIONS .................................................................................................................. 4
» CHASSIS LAYOUT ............................................................................................................................. 10
» BLOCK DIAGRAM ..............................................................................................................................11
» SCHEMATIC DIAGRAMS ...................................................................................................................12
» PRINTED WIRING BOARD ASSEMBLIES ........................................................................................ 18
» REPLACEMENT PARTS LIST ............................................................................................................21
» PACKING OF THE SET ...................................................................................................................... 27
POWER INPUT .................................................... 120 V AC 60 Hz
POWER RATING ................................................................... 92 W
PICTURE SIZE ................................................. Approx. 267 sq. in.
CONVERGENCE ............................................................. Magnetic
SWEEP DEFLECTION .................................................... Magnetic
FOCUS .................................................................... Hi-Bi-potential
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 ................................................ 1.5 W + 1.5 W
(at 10% Distortion and Dual CH Operate)

SERVICE MANUAL

CONTENTS
ELECTRICAL SPECIFICATIONS
SPEAKER
ANTENNA INPUT IMPEDANCE
TUNING RANGES
(Nominal)

SHARP CORPORATION

1
COLOR TELEVISION
Chassis No. SN-70A
25MR15J
MODEL
SIZE ...................................................................... 8 cm (Round)
VOICE COIL IMPEDANCE ............................ 32 ohm at 400 Hz
VHF/UHF ................................................... 75 ohm Unbalanced
All 12 television channels ............................ 54 MHz to 88 MHz
Any of 56 UHF channels .......................... 470 MHz to 806 MHz
CATV Channels (1.14 thru 125) ........ 72. 120 MHz to 804 MHz
Specifications are subject to change without
prior notice.
25MR15J
S21Q225MR15J/
Page
174 MHz to 214 MHz

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Summary of Contents for Sharp 25MR15J

  • Page 1: Table Of Contents

    25MR15J SERVICE MANUAL S21Q225MR15J/ COLOR TELEVISION Chassis No. SN-70A 25MR15J MODEL 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

    25MR15J IMPORTANT SERVICE SAFETY PRECAUTION Ë Service work should be performed only by qualified service technicians who are throughly 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

    25MR15J 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: Service Instructions

    25MR15J 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. CIRCUIT PROTECTION X-RADIATION PROTECTOR CIRCUIT TEST The receiver is protected by a 4.0A fuse (F701),...
  • Page 5 25MR15J SERVICE INSTRUCTIONS 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.
  • Page 6 25MR15J SERVICE INSTRUCTIONS DATA SERVICE ADJUSTMENT ITEM ADJUSTMENT CONTENTS NUMBER RANGE INITIAL VALUE PICTURE 00-7F TINT 00-7F COLOR 00-7F BRIGHTNESS 00-7F SHARPNESS 00-3F Must be set to "28" VERTICAL PHASE 00-07 Must be set to "00" HORIZONTAL PHASE 00-1F RF-AGC...
  • Page 7: Service Adjustment

    25MR15J SERVICE INSTRUCTIONS Ë SERVICE ADJUSTMENT Note: Before making the service adjustment, make he 4. Select the service adjustment "S19" and adjust the bus data settings. data value to "01", this turn off the luminance signal (Y-mute). +B ADJUSTMENT 5. Select the service adjustment "S04" and adjust data 1.
  • Page 8 25MR15J SERVICE INSTRUCTIONS SUB-BRIGHTNESS ADJUSTMENT 3.58MHz TRAP ADJUSTMENT 1. Receive a good local channel. 1. Receive a good local channel. 2. Make sure the customer brightness control is set to 2. Enter the service mode and select the service center position.
  • Page 9: Mts Adjustment

    25MR15J SERVICE INSTRUCTIONS Ë MTS ADJUSTMENT MTS LEVEL ADJUSTMENT SEPARATION ADJUSTMENT 1. Feed the following monaural signal to pin (14) of 1. Connect the rms voltmeter to pin (39) of IC3001. IC3001. 2. Receive the following composite stereo signal 1.
  • Page 10: Chassis Layout

    25MR15J CHASSIS LAYOUT...
  • Page 11: Block Diagram

    25MR15J BLOCK DIAGRAM...
  • Page 12: Schematic Diagrams

    25MR15J DESCRIPTION OF SCHEMATIC DIAGRAM NOTES: SAFETY NOTES: 1. The unit of resistance "ohm" is omitted. 1. DISCONNECT THE AC PLUG FROM THE AC OUTLET BE- (K = k Ω = 1000 Ω , M = M Ω ) FORE REPLACING PARTS.
  • Page 13 25MR15J SCHEMATIC DIAGRAM: CRT and FRONT AV Unit...
  • Page 14 SCHEMATIC DIAGRAM: MAIN-1 Unit 14~15...
  • Page 15 SCHEMATIC DIAGRAM: MAIN-2 Unit 16~17...
  • Page 16: Printed Wiring Board Assemblies

    25MR15J PRINTED WIRING BOARD ASSEMBLIES PWB-A: MAIN Unit (Wiring Side)
  • Page 17 25MR15J PWB-A: MAIN Unit (Chip Parts Side)
  • Page 18 25MR15J PWB-B: CRT Unit (Wiring Side) PWB-H: FRONT AV Unit (Wiring Side)
  • Page 19: Replacement Parts List

    25MR15J Ref. No. Part No. Description Code Ref. No. Part No. Description Code PARTS LIST PWB-A: DUNTKA216WEV3 PARTS REPLACEMENT MAIN UNIT Replacement parts which have these special safety characteristics identified in this manual; electrical components having such features TUNER are identified by...
  • Page 20 25MR15J Ref. No. Part No. Description Code Ref. No. Part No. Description Code PWB-A: DUNTKA216WEV3 C206 VCEA0A1CW337M J 330 C207 VCKYCY1HF103Z J 0.01 Ceramic MAIN UNIT (Continued) C208 VCEA0A1HW474M J 0.47 C209 VCKYCY1HB222K J 2200p 50V Ceramic D705 VHD1SS244//-1 J Diode...
  • Page 21 25MR15J Ref. No. Part No. Description Code Ref. No. Part No. Description Code PWB-A: DUNTKA216WEV3 RJ35 VRN-MD2AL000J 1/10W M-Film. RJ36 VRN-MD2AL000J 1/10W M-Film. MAIN UNIT (Continued) RJ37 VRN-MD2AL000J 1/10W M-Film. RJ38 VRN-MD2AL000J 1/10W M-Film. C723 RC-EZ0724CEZZ J 100 160V EL.
  • Page 22 25MR15J Ref. No. Part No. Description Code Ref. No. Part No. Description Code PWB-A: DUNTKA216WEV3 R2023 VRN-MD2AL223J J 22k 1/10W M-Film. R2024 VRD-RA2BE682J J 6.8k 1/8W Carbon MAIN UNIT (Continued) R2025 VRD-RA2BE682J J 6.8k 1/8W Carbon R2026 VRD-RA2BE682J J 6.8k 1/8W...
  • Page 23: Crt Unit

    25MR15J Ref. No. Part No. Description Code Ref. No. Part No. Description Code PWB-A: DUNTKA216WEV3 PWB-B: DUNTK9910WEV1 MAIN UNIT (Continued) CRT UNIT TRANSISTORS FB702 RBLN-0036CEZZ J Ferrite Bead FB704 RBLN-0037CEZZ J Ferrite Bead Q851 VS2SC3198-Y-1 J 2SC3198 (Y) FB706 RBLN-0037CEZZ...
  • Page 24: Cabinet Parts

    25MR15J Ref. No. Part No. Description Code Ref. No. Part No. Description Code PWB-H: DUNTK9310WEV1 CABINET PARTS FRONT AV UNIT MISCELLANEOUS PARTS CCABA2666WEV0 R Cabinet J1001 QJAKE0053GEZZ J Jack, Video IN Not Available – Front Cabinet — J1002 QJAKE0055GEZZ J Jack, Audio IN (L)
  • Page 25: Packing Of The Set

    25MR15J Ref. No. Part No. Description Code Ref. No. Part No. Description Code PACKING OF THE SET Polyethylene Bag Operation Manual Batteries Polyethylene Sheet Infrared R/C unit Buffer Material FRONT Packing Case Use 22 staples to fix the bottom side of packing case.
  • Page 26 Code Ref. No. Part No. Description Code COPYRIGHT © 2000 BY SHARP CORPORATION ALL RIGHTS RESERVED. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher.

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