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Memorex MT2274A Service Manual

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MT2274A
SERVICE MANUAL
COLOR TELEVISION RECEIVER
ORIGINAL
MFR'S VERSION A
Design and specifications are subject to change without notice.

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Summary of Contents for Memorex MT2274A

  • Page 1 MT2274A SERVICE MANUAL COLOR TELEVISION RECEIVER ORIGINAL MFR'S VERSION A Design and specifications are subject to change without notice.

  • Page 2: Servicing Notices On Checking

    SERVICING NOTICES ON CHECKING 1. KEEP THE NOTICES 6. AVOID AN X-RAY As for the places which need special attentions, Safety is secured against an X-ray by consider- they are indicated with the labels or seals on the ing about the cathode-ray tube and the high cabinet, chassis and parts.

  • Page 3: Table Of Contents

    CONTENTS SERVICING NOTICES ON CHECKING ......................A1-1 HOW TO ORDER PARTS ..........................A1-1 IMPORTANT ..............................A1-1 CONTENTS ..............................A2-1 GENERAL SPECIFICATIONS ........................A3-1~A3-4 DISASSEMBLY INSTRUCTIONS 1. REMOVAL OF ANODE CAP ......................... B1-1 2. REMOVAL AND INSTALLATION OF FLAT PACKAGE IC ..............B2-1, B2-2 SERVICE MODE LIST .............................

  • Page 4: General Specifications

    GENERAL SPECIFICATIONS CRT Size / Visual Size 27 inch / 676.0mmV System CRT Type Normal Magnetic Field BV/BH +0.45G/0.18G Color System NTSC Speaker 2Speaker Position Front Size 2.0 x 3.5 Inch Impedance Sound Output 2.5 + 2.5 W 10%(Typical) NTSC3.58+4.43 /PAL60Hz Tuning Broadcasting System System M...
  • Page 5 GENERAL SPECIFICATIONS Back Light Stereo,Audio Output,SAP Video Color Stream Channel(TV/Cable) CH Label Sleep Timer Sound Mute V-chip Rating OSD Language English French Spanish Clock and Sleep Timer Max Time 120 Min Timer Step On/Off Timer Program(On Timer / Off Timer) Wake Up Timer Timer Back-up (at Power Off Mode) more than...
  • Page 6 GENERAL SPECIFICATIONS CATV Anti-theft Rental Memory(Last CH) Memory(Last Volume) V-Chip Type USA, ORION Type Auto Search CH Allocation Tone Control Channel Lock Just Clock Function Game Position CH Label VM Circuit Full OSD Premiere Comb Filter Lines Auto CH Memory Hotel Lock Closed Caption Stable Sound...
  • Page 7 GENERAL SPECIFICATIONS On Timer Terminals Front Video Input Audio Input RCA x 2 Other Terminal Rear Video Input(Rear1) Video Input(Rear2) Audio Input(Rear1) RCA x 2 Audio Input(Rear2) Video Output Audio Output S-Input Color Stream Diversity Ext Speaker DC Jack 12V(Center +) VHF/UHF Antenna Input F Type AC Outlet...

  • Page 8: Disassembly Instructions

    DISASSEMBLY INSTRUCTIONS 3. After one side is removed, pull in the opposite direction to 1. REMOVAL OF ANODE CAP remove the other. Read the following NOTED items before starting work. NOTE After turning the power off there might still be a potential Take care not to damage the Rubber Cap.

  • Page 9: Removal And Installation Of Flat Package Ic

    DISASSEMBLY INSTRUCTIONS REMOVAL AND INSTALLATION OF When IC starts moving back and forth easily after desoldering completely, pickup the corner of the IC using FLAT PACKAGE IC a tweezers and remove the IC by moving with the IC desoldering machine. (Refer to Fig. 2-3.) REMOVAL NOTE Put Masking Tape (cotton tape) around the Flat Package...
  • Page 10 DISASSEMBLY INSTRUCTIONS INSTALLATION When bridge-soldering between terminals and/or the soldering amount are not enough, resolder using a Thin- Take care of the polarity of new IC and then install the tip Soldering Iron. (Refer to Fig. 2-8.) new IC fitting on the printed circuit pattern. Then solder each lead on the diagonal positions of IC temporarily.

  • Page 11: Service Mode List

    SERVICE MODE LIST This unit is provided with the following SERVICE MODES so you can repair, examine and adjust easily. To enter the Service Mode, press both set key and remote control key for more than 2 seconds. Set Key Remocon Key Operations VOL.

  • Page 12: Electrical Adjustments

    ELECTRICAL ADJUSTMENTS 1. ADJUSTMENT PROCEDURE 2. BASIC ADJUSTMENTS Read and perform these adjustments when repairing the 2-1: CONSTANT VOLTAGE circuits or replacing electrical parts or PCB assemblies. Place the set in AV MODE without signal. CAUTION Connect the digital voltmeter to the TP401. Adjust the VR502 until the digital voltmeter is 120 ±...
  • Page 13 ELECTRICAL ADJUSTMENTS 2-6: VERTICAL SIZE 2-11: SEPARATION 1, 2 Receive the monoscope pattern. Please do the method (1) or method (2) adjustment. Using the remote control, set the brightness and contrast Method (1) to normal position. Set the multi-sound signal generator for each different L-ch Activate the adjustment mode display of Fig.
  • Page 14 ELECTRICAL ADJUSTMENTS 2-13: BRIGHT CENT Receive the monoscope pattern. (RF Input) Using the remote control, set the brightness and contrast to normal position. Activate the adjustment mode display of Fig. 1-1 and press the channel button (13) on the remote control to select "BRI CENT".
  • Page 15 ELECTRICAL ADJUSTMENTS 3-3: STATIC CONVERGENCE 3. PURITY AND CONVERGENCE ADJUSTMENTS NOTE Adjust after performing adjustments in section 3-2. NOTE Receive the crosshatch pattern from the color bar Turn the unit on and let it warm up for at least 30 generator.
  • Page 16 ELECTRICAL ADJUSTMENTS 4. ELECTRICAL ADJUSTMENT PARTS LOCATION GUIDE (WIRING CONNECTION) CRT PCB TP024 TP022 J801 CP802B CP803B CD802 CD803 CP803A J705 J701 CP601 VR403 VR401 FB401 VR404 VR402 TU001 VR502 TP401 CP1001 DEGAUSS COIL SPEAKER CP502 CP802A S501B CD501 S501A J712 J711 J710...

  • Page 17: Block Diagram

    BLOCK DIAGRAM J705 CH. DOWN MICON/CHROMA IC VOL. DOWN IC101 OEC7091C 24 26 CH. UP RGB Proc.2 VOL. UP Q801, Q804 OSD SW CONTRAST BRIGHTNESS RED AMP RGB OUTPUT Stage POWER Chroma Proc. DRIVE Q803, Q805 ACC/C-BPF CUT OFF OS101 GREEN AMP APC/KILLER HV BLK...

  • Page 18: Printed Circuit Boards Main/Crt

    PRINTED CIRCUIT BOARDS MAIN/CRT (INSERTED PARTS) SOLDER SIDE J710 J711 SW105 J712 SW102 W012 SW101 SW104 SW103 R603_1 TP024 TCD461D C505 F501 FH501 Q603 W011 S501A Q608 TP022 W815 R630 D604 W010 W031 S501B Q602 TP023 Q607 R629_1 CD802A W009 CP802A W007 R500...
  • Page 19 PRINTED CIRCUIT BOARDS MAIN/CRT (CHIP MOUNTED PARTS) SOLDER SIDE R722 R708 R707 Q407 R004 R003 Q901 Q902 TMD605D R532 R533 R534 Q507 IC901 R006 R1019 Q1003 R129 R601 R123 R113 R115 R131 IC199_1 R604 R813 R809 R816 R627 C642 R617 R810 R609 R621...
  • Page 20 MICON/CHROMA/TUNER SCHEMATIC DIAGRAM (MAIN PCB) ACCESSORY H.CTL Q607 R621 KTC3198 FROM AV R618 TM101 Y_IN RC-DW130 8.2K 1/4W FROM/TO DEFLECTION/CRT R608 C118_2 C630_1 CLAMP R124 1/4W 1/4W C653 C101 V_OUT R110 C632_1 0.01 R109 V_FEEDBACK AT+5V ABCL P.CON+8V[B] H_OUT X-RAY R108 100 1/4W C629 C623_1...
  • Page 21 DEFLECTION/CRT SCHEMATIC DIAGRAM (TV MT PCB) FROM/TO MICON/CHROMA/TUNER CP802A B2013H02-5P CP802B B2013H02-5P C813 CLAMP CLAMP CLAMP CLAMP CLAMP 0.001 G.OUT G.OUT G.OUT G.OUT G.OUT R.OUT R.OUT R.OUT R.OUT R.OUT V-OUT IC IC401 LA78041 B.OUT B.OUT B.OUT B.OUT B.OUT V_OUT THERMAL CP803A B2013H02-4P CP803B B2013H02-4P...
  • Page 22 POWER SCHEMATIC DIAGRAM (TV MT PCB) D516 1SS133 RELAY DRIVE TO DEFLECTION/CRT Q504 R521 KTC3198 RY501 UNREG+18V G5PA-1-SA(WEC) 150 2W T501 81400694 15.6 C516 140.5 15.6 W848 R517_1 TO SOUND 500V 0.0022 140.5 0.39 SOUND+B DEGAUSS COIL L503 D505 144.0 8R270010 CP502 A1561WV2-2PK...
  • Page 23 SOUND SCHEMATIC DIAGRAM (MAIN PCB) FROM/TO MICON/CHROMA/TUNER R308 AUDIO_MUTE VOLUME 2.2K 1/4W BUFFER Q901 2SA1530A1 R319 BUFFER W852 Q902 2.2K IIC Decoder St.PLL OUT SW 2SA1530A1 Pilot Input W894 Cancel Switch L-R Filter L-R Demod Matrix De-Emph (L-R)/SAP Pilot Filter Filter Filter 75us...
  • Page 24 AV SCHEMATIC DIAGRAM (TV MT PCB) VIDEO_3_IN AV (FRONT) J710 C702_1 R733 MTJ-032-03A-30FE C701_1 R734 L3_IN AV (FRONT) J711 MTJ-032-03A-32FE R3_IN AV (FRONT) J712 TO SOUND R740 MTJ-032-03A-31FE FRONT_AUDIO_L FRONT_AUDIO_R REAR_AUDIO_R REAR_AUDIO_L C729_2 R724 1/4W S_VIDEO FROM/TO POWER J705 YKF51-5503N C727 TO MICON/CHROMA/TUNER C709_1...

  • Page 25: Micon/Chroma/Tuner

    WAVEFORMS MICON/CHROMA/TUNER 200V 20µs/div 1V 20µs/div 20V 20µs/div 10V 5ms/div 200mV 20µs/div 3 200mV 20µs/div DEFLECTION/CRT 10V 5ms/div 14 0.5V 5ms/div 0.5V 5ms/div 50V 20µs/div 15 20V 20µs/div 5 1V 20µs/div 6 1V 20µs/div 16 2V 20µs/div 21 50V 20µs/div NOTE: The following waveforms were measured at the point of the corresponding balloon number in the schematic diagram.

  • Page 26: Sound

    WAVEFORMS 31 200mV 1ms/div 22 50V 20µs/div SOUND 25 0.5V 1ms/div 0.5V 1ms/div 26 200mV 1ms/div 0.5V 1ms/div 200mV 1ms/div 28 200mV 1ms/div NOTE: The following waveforms were measured at the point of the corresponding balloon number in the schematic diagram.

  • Page 27: Mechanical Exploded View

    MECHANICAL EXPLODED VIEW 102B 102C PCB110 (CRT PCB ASS'Y) J801 102A 102C FB401 202 208 V801 TU001 PCB010 (MAIN PCB ASS'Y) 101D SP1001 101C 101E 101A 101B...

  • Page 28: Mechanical Replacement Parts List

    MECHANICAL REPLACEMENT PARTS LIST REF. NO. PART NO. DESCRIPTION 7A701A271A FRONT,CABI ASS'Y 101A 701WPJC873 CABINET,FRONT 101B 711WPCA043 BADGE,BRAND 101C 713WPAA170 GUIDE,REMOCON 101D 735WPBB277 BUTTON,ASS'Y 101E 800WQ0A049 FELT,SHEET 9x220xT=0.3 7A702A080A BACK,CABI ASS'Y 102A 702WPAA792 CABINET,BACK 102B 800WQ0A046 FELT,SHEET 9x220xT=0.5 102C 800WQ0A090 FELT,SHEET 9x350xT=0.5 800WQ0A067 FELT,SHEET 5x30xT=0.5...

  • Page 29: Electrical Replacement Parts List

    ELECTRICAL REPLACEMENT PARTS LIST REF. NO. PART NO. DESCRIPTION REF. NO. PART NO. DESCRIPTION RESISTORS DIODES ! R402 R3K181102J R,METAL OXIDE OHM 1W ! D504 D2WTRM11C0 DIODE SILICON RM11C-EIC ! R408 R4X5T6392F R,METAL 3.9K OHM 1/6W D505 D28F30DF60 DIODE RECTIFIER 30DF6-FC ! R409 R4X5T6153F R,METAL...
  • Page 30 ELECTRICAL REPLACEMENT PARTS LIST REF. NO. PART NO. DESCRIPTION JACKS ! J801 066F130021 SOCKET,CATHODE RAY,TUBE ISHS62S SWITCHES SW101 0504101T34 SWITCH,TACT EVQ21505R SW102 0504101T34 SWITCH,TACT EVQ21505R SW103 0504101T34 SWITCH,TACT EVQ21505R SW104 0504101T34 SWITCH,TACT EVQ21505R SW105 0504101T34 SWITCH,TACT EVQ21505R VARIABLE RESISTORS VR401 V1K63H3BTE VOLUME,SEMI FIXED NVG6TLTAB222 VR402...
  • Page 31 M3T1-09D SPEC.NO. W523015 O/R NO.
  • Page 32 MT2274A SERVICE MANUAL COLOR TELEVISION RECEIVER REVISION 1 MFR'S VERSION B MFR'S VERSION PRODUCT IMPROVEMENT SH COMPLIANT Please file the revision with the original version.
  • Page 33 Change of SH COMPLIANT ELECTRICAL REPLACEMENT PARTS LIST MFR'S VERSION A MFR'S VERSION B PART NO. DESCRIPTION PART NO. DESCRIPTION REF. NO. TM101 076N0DW130 TRANSMITTER RC-DW130 076N0DW190 TRANSMITTER RC-DW190 MAIN PCB ASS'Y (VERSION A) MAIN PCB ASS'Y (VERSION B) PCB010 A3T109D010 A3T118D010 TMD605D...
  • Page 34 MT2274A SERVICE MANUAL COLOR TELEVISION RECEIVER REVISION 2 MFR’S VERSION C PRODUCT IMPROVEMENT MFR’S VERSION A68KTB359X058(PL) SH COMPLIANT M68LWF088X50 Please file the revision with the original version.
  • Page 35 Change of CRT ELECTRICAL REPLACEMENT PARTS LIST MFR'S VERSION B MFR'S VERSION C PART NO. DESCRIPTION PART NO. DESCRIPTION REF. NO. CRT W/DY CRT W/DY ! V801 098B270602 0981270B01 A68KTB359X058(PL) M68LWF088X50 R419 R002T4821J RC 820 OHM 1/4W R002T4102J RC OHM 1/4W ! R429 R638812R2J R,FUSE 2.2 OHM 1W...
  • Page 36 DEFLECTION/CRT SCHEMATIC DIAGRAM (MAIN PCB) (MFR'S VERSION C) ADD C450 R819 MICON/CHROMA/TUNER SCHEMATIC DIAGRAM (MAIN PCB) (MFR'S VERSION C) ADD C643 SPEC.NO. M3T1-132 O/R NO. W5Z3067...

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