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AOC LM721A Service Manual

17 lcd monitor
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SERVICE MANUAL
17" LCD Monitor
LM721A Srial
Date: Jul-02-03
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  • Page 1 All manuals and user guides at all-guides.com SERVICE MANUAL 17” LCD Monitor LM721A Srial Date: Jul-02-03 Page Page Page Page 1 1 1 1 of of of of 59 59 59 59...

  • Page 2: Monitor Specifications

    All manuals and user guides at all-guides.com Serial Service Manual Rev: A LM721A 1.MONITOR SPECIFICATIONS Driving system TFT Color LCD LCD Panel Size 43.2cm(17.0") Pixel pitch 0.264mm( H )x 0.264mm( V ) Viewable angle 150˚ (H) 110˚ (V) Response time (typ.)

  • Page 3: Lcd Monitor Description

    2. LCD MONITOR DESCRIPTION All manuals and user guides at all-guides.com The LCD MONITOR will contain a main board, an inverter/power board, keypad board , Audio board and external power adapter which house the flat panel control logic, brightness control logic and DDC. The Inverter board will drive the backlight of panel and the DC-DC conversion.

  • Page 4: General Instructions

    All manuals and user guides at all-guides.com Serial Service Manual Rev: A LM721A 3. OPERATING INSTRUCTIONS 3.1 GENERAL INSTRUCTIONS Press the power button to turn the monitor on or off. The other control buttons are located at front panel of the monitor. By changing these settings, the picture can be adjusted to your personal preferences.

  • Page 5: Osd Table

    OSD Table: All manuals and user guides at all-guides.com Contrast Adjust the picture contrast. Brightness Adjust the picture brightness. Focus Adjust picture Focus. Clock Adjust picture Clock. H_Position Adjust the horizontal position of the picture. V.Position Adjust the vertical position of the picture. Input Signal source sleeted (select Analog or Digital input Input Selected source).

  • Page 6: Input Signal Connector

    4.1 Input Signal Connector All manuals and user guides at all-guides.com PIN NO. DESCRIPTION DESCRIPTION PI N NO. Green Detect Cable Blue Ground DDC-Serial Data Ground H-Sync R-Ground V-Sync G-Ground DDC-Serial Clock B-Ground VGA connector layout Page Page 9 9 9 9 of of of of 59 59 59 59 Page Page...

  • Page 7: Vesa Modes

    All manuals and user guides at all-guides.com VESA MODES Horizontal Vertical Nominal Sync Nominal Sync Nominal Pixel Mode Resolution Total Frequency Polarity Freq. Polarity Clock +/- 0.5kHz +/- 1 Hz (MHz) 640x480@60Hz 800 x 525 31.469 59.940 25.175 640x480@72Hz 832 x 520 37.861 72.809 31.500...
  • Page 8 4.3.1 Input Requirements All manuals and user guides at all-guides.com PARAMETER RANGE CONDITION Input AC Voltage 100 to 240VAC RMS Universal input full range Input Frequency 60Hz @ 100VAC to 50Hz @ 240VAC Input Current Less than 2.0 Amps RMS Input voltage 100 VAC RMS ;...
  • Page 9 4.4 PANEL SPECIFICATION (Hydis-200) All manuals and user guides at all-guides.com 4.4.1 Panel Feature -High contrast ratio, high aperture structure -TN(Twisted Nematic) mode -Wide viewing angle -High speed response -SXGA(1280 x 1024 pixels) resolution -Low power consumption -2 dual CCFTs(Cold Cathode Fluorescent Tube) -DE(Data Enable) mode -COMPACT SIZE DESIGN 4.4.2 Display Characteristics...
  • Page 10 All manuals and user guides at all-guides.com Serial Service Manual Rev: A LM721A 4.4.4 Parameter guide line for CCFL Inverter INVERTER MAX BRINGTHNESS (Vadj:5.0v), LOAD=120KΩX4(ROOM TEMPERATURE 25℃ ±4℃) ITEM SYMBOL MIN. TYP. MAX. UNIT REMARK Input voltage 10.8 13.2 Input current...
  • Page 11 All manuals and user guides at all-guides.com...

  • Page 12: Software Flow Chart

    2 Software Flow Chart All manuals and user guides at all-guides.com Page Page 15 15 15 15 of of of of 59 59 59 59 Page Page...
  • Page 13 Remark: All manuals and user guides at all-guides.com 1) MCU initialize. 2) Is the EEprom blank ? 3) Program the EEprom by default values. 4) Get the PWM value of brightness from EEprom. 5) Is the power key pressed ? 6) Clear all global flags.
  • Page 14 5.3.1 Main Board All manuals and user guides at all-guides.com Interface (CN301) LVDS THC63LVDM83R (U301/U302) Scalar gm5120/gm2120 (Include MCU,ADC,OSD) Flash Memory W39f010P-70B (U202) (U203) Hsync, EPR_SDA Vsync EPR_SCL DVI-I only Control EEPROM D-Sub Connector 24C16 Connector Interface (CN101) (CN403) (U204) (CN102) DB15_SDA, DB15_SCL...

  • Page 15: Inverter/Power Board

    2 Inverter/Power Board All manuals and user guides at all-guides.com Inverter Block Diagram P a r a lle t- re s o n a n t V in B u c k C o n n e c to r in v e rte r D r iv e r D im m in g c o n tro l...

  • Page 16: Power Block Diagram

    All manuals and user guides at all-guides.com Service Manual Rev: A LM721A Power Block Diagram Page Page Page Page 19 19 19 19 of of of of 59 59 59 59...
  • Page 17 6.1 Main Board All manuals and user guides at all-guides.com 10/16 modify CN101 RX2-IN A_GND RX2- RX2+IN RX2+ SGND ED102 Connect two grounds at o ED101 SCL_IN DDCCLK SCL_IN SDA_IN SDA_IN DDCDAT VS_DVI A_VSYNC R102 R102¹qªý½Ð¾aªñ ANALOG PORT D-SUB RX1-IN AGND RX1- RX1+IN...
  • Page 18 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A FB201 FB202 +A3.3V +A3.3V FB208 +2.5V 3.3V_DDDS Close to respective power Pins C222 C224 C225 C223 +A3.3V 22uF/16V 22uF/16V C259 FB209 0.1uF/16V 0.1uF/16V C212 100uF/16V C211 +A3.3V C213...
  • Page 19 Service Manual Rev: A LM721A All manuals and user guides at all-guides.com A3.3V AU17 LVDS INTERFACE 10/16 modify +3.3V A3.3V FB301 C300 C301 C302 C329 600OHM CHANGE B G R DATE SIGNAL 4/18 0.1uF/16V 100uF/16V 0.1uF/16V 0.1uF/16V 4/29 ADD S/W TEST PBIAS CONTROLL...
  • Page 20 U103 AIC1084CM ON/OFF Vout 33A8009-12G-H C106 C107 C112 470 uF/16V 470 uF/16V 0.1U/25V R107 AOC (Top Victory) Electronics Co., Ltd. is power GND Title 1.POWER R108 Size Document Number IDPC7425A6(715L963-1-2) is signal GND Date: Friday, August 16, 2002 Sheet INVERTER SCHEMATICS...
  • Page 21 R223 12K R211 R219 Q212 1U/25V BAV99 C206 2SD2098 0.1U/25V R235 680 D208 R241 RLS4148 AOC (Top Victory) Electronics Co., Ltd. C222 C220 is power GND R239 R237 560 Title 0.47U/25V 1U/25V 2. FOR SAMSUNG LTM170EU-L01 INVERTER Size Document Number ID7425A6(715L963-1-2)
  • Page 22 3\8009-12G-H CON203 120K 12V or 14V DC POWER SUPPLY SM02(8.0)B-BHS-1-TB CON204 120K MMST3904 5.6B SM02(8.0)B-BHS-1-TB AOC (Top Victory) Electronics Co 0V~5V Title CONVERTER&INVERTER FUNCTIO Size Document Number IDPC7425A6(715A963-1-2) Date: Saturday, July 13, 2002 Sheet Page Page 25 25 25 25 of of of of 59 59 59 59...
  • Page 23 6.3 Key Board All manuals and user guides at all-guides.com U106D +12V LED_ORANGE R420 C418 U106C 74LVC14 0.1uF/16V LED_GRN Q406 CN401 Q405 R419 R418 MUTE STDBY SP(L) SP(R) C423 150pF 74LVC14 Earphone(L) Earphone(R) OUT(L) OUT(R) FB403 FB404 +A3.3V R402 R401 5/10 change A+3.3V CON12A(PITCH 2.0) STDBY...
  • Page 24 Main Board All manuals and user guides at all-guides.com Page Page 27 27 27 27 of of of of 59 59 59 59 Page Page...
  • Page 25 Inverter/Power Board All manuals and user guides at all-guides.com Page Page 28 28 28 28 of of of of 59 59 59 59 Page Page...

  • Page 26: Audio Board

    7.3 Keypad Board and Audio board All manuals and user guides at all-guides.com 1. Keypad Board 2.Audio Board Page Page 29 29 29 29 of of of of 57 57 57 57 Page Page...

  • Page 27: Equipments And Tools Requirement

    8. Maintainability All manuals and user guides at all-guides.com 8.1 Equipments and Tools Requirement 1.) Voltmeter. 2.) Oscilloscope. 1.) Pattern Generator. 2.) DDC Tool with a IBM Compatible Computer. 3.) Alignment Tool. 4.) LCD Color Analyzer. 5.) Service Manual. 6.) User Manual. Page Page 30 30 30 30 of of of of 57 57 57 57 Page...

  • Page 28: Troubleshooting

    8.2 Trouble Shooting All manuals and user guides at all-guides.com 8.2.1 Main Board 1.NO SCREEN APPEAR Measured CN402 pin 9/10 = 2.5 V? Check Correspondent component. Measured CN402 pin 7/8= 3.3V? Is there any shortage or cold solder? Measured CN402 pin 3/4= 5V? Measured CN402 pin 12= 12V? Yes.
  • Page 29 2.PANEL-POWER CIRCUIT All manuals and user guides at all-guides.com Check the PPWR panel power relative circuit, check R302 should have response from 0V to 5V Q301, Q302(pin 5,6,7,8) When we switch the power switch from on to off In normal operation, when LED =green, R302 should =0 v, OK, R308 have NG, no Voltage...
  • Page 30 4.U203-DATA OUTPUT All manuals and user guides at all-guides.com NG , no transition Measured DCLK(R240) DVS, DHS (pin 117,116 from U203 ) Is the waveform ok? DCLK around 48 MHZ , DVS=60.09Hz , DHS around 80 KHz ?(refer to input Replace GM5120 /2120 (U203) or signal=640x480@60 Hz 31k, and LED is replace MAINBOARD.

  • Page 31: Power/Inverter Board

    8.2.2 Power/Inverter Board All manuals and user guides at all-guides.com 1.) No power Check to CN102 Pin1 and pin2 = 5V Check Interface board Check AC line volt 120V or 220V Change F901 , check BD901,Q903,IC901 Check the voltage of C905(+) Check bridge rectified circuit Check start voltage for the pin3 of IC901 Change IC901...
  • Page 32 2.) W / LED , No Backlight All manuals and user guides at all-guides.com Check Fuse F101 =12V To change Check ON/OFF signal Check Interface board Check U201 pin9=12V Change Q201 or Q202 Check the pin1 of U201 have correct wave Change U201 Check D201(-),D202(-) have the output of square wave at short time.

  • Page 33: Keypad Board

    Service Manual Rev: A LM721A All manuals and user guides at all-guides.com 8.2.3 KeyPad Board OSD is unstable or not working Connect KeyPad Board Is KeyPad Board connecting normally ? Replace Button Switch Is Button Switch normally ? Replace KeyPad Board...

  • Page 34: White-Balance, Luminance Adjustment

    Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 9. White-Balance, Luminance adjustment Approximately 30 minutes should be allowed for warm up before proceeding white balance adjustment. Before started adjust white balance ,please setting the Chroma-7120 MEM. channel 1 to 6500 color, MEM. channel 2 to 7800 color, ( our 6500 parameter is x = 313 ±10, y = 329 ±10, Y = 200 ±10 cd/m...
  • Page 35 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 10. EDIT Content A. D-SUB Connector (Analog) Note: Byte 0C, 0D, 0E, 0F means Serial No. Byte 10, 11 means Manufacture Time. Byte 7F means checksum B. DVI Connector (Digital) Note: Byte 0C, 0D, 0E, 0F means Serial No.

  • Page 36: Warranty Card

    Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 11. BOM List ADPC12416AE LCD ADAPTER ASS'Y AUDIO BOARD FOR AUPC782A3 T780K* CBPC782KADA CONVERSION BOARD IDPC7425A1 LCD INVERTER BOARD KEY BOARD FOR KEPC780KA9 T780K*SNI WOODEN PALLET 0.0067 WOODEN PALLET 0.0067...
  • Page 37 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 瞀 à 狾 44L9003210 0.054 45L 76 28 RN pe bag for base/MANUAL 45L 77500 BARCODE RIBBON 45L 77501 BARCODE RIBBON 45L 77511 45L 88500 1 PE BAG 0.0067...
  • Page 38 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A ADPC12416AB6 LCD ADAPTER A6 ASS'Y 2 GND1 9L6002 1 40L 581700 6A LABEL 1.05 6 4500 1213600 簧 盿 2 IC903 56L 139 3B PC123 Y82 2 R911...
  • Page 39 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 705L 560 61 04 NR901 ASS'Y 715L 901 1 4 ADAPTOR 705L 560 57 03 Q901 ASS'Y 705L 560 61 03 R930 ASS'Y 705L 780 93 03 D911 ASS'Y...
  • Page 40 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 R916 61L0805472 CHIRP 4.7K OHM +-5% 1/1 3 R917 61L0805472 CHIRP 4.7K OHM +-5% 1/1 3 R918 61L0805472 CHIRP 4.7K OHM +-5% 1/1 3 R920 61L0805623 CHIPR 62K OHM +-5% 1/10...

  • Page 41: Phone Jack

    Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 D904 93L 6432V LL4148-GS08 3 D905 93L 6432V LL4148-GS08 3 ZD901 93L 39S500 T 19VZENER PIODE 33L6007 1 LENS HI-POT GND LABEL FOR 40L 154501 1 40L416B615 1A ADAPTER ID LABEL 1.02...

  • Page 42: Main Board

    Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 90L6059 1 床荐 715L 964 2 AUDIO BOARD 60*45 3 J1 95L 90 23 TIN COATED 3 J2 95L 90 23 TIN COATED 3 J3 95L 90 23...
  • Page 43 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A ň 聁瞜奎 55L 100600 A 55L 100603 瞜奎 2 U202 56L1133 41 A1 W39F010U 2 U202 56L1133 42 A1 A290011T-70 LOW ESR 150UF 25V 2 C401 67L215C151 4H...
  • Page 44 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 R227 61L0603000 CHIPR 0OHM +-5% 1/16W 3 R235 61L0603000 CHIPR 0OHM +-5% 1/16W 3 R305 61L0603000 CHIPR 0OHM +-5% 1/16W 3 R307 61L0603000 CHIPR 0OHM +-5% 1/16W...
  • Page 45 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 R123 61L0603153 CHIPR 15KOHM+-5% 1/16W 3 R124 61L0603153 CHIPR 15KOHM+-5% 1/16W 3 R131 61L0603222 CHIPR 2.2K OHM+-5% 1/16 3 R132 61L0603222 CHIPR 2.2K OHM+-5% 1/16 3 R204 61L0603272 CHIP 2.7K OHM 1/16W...
  • Page 46 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 C109 65L0603104 12 0.1UF +-10% 16V X7R 3 C113 65L0603104 12 0.1UF +-10% 16V X7R 3 C201 65L0603104 12 0.1UF +-10% 16V X7R 3 C202 65L0603104 12 0.1UF +-10% 16V X7R...
  • Page 47 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 C249 65L0603104 12 0.1UF +-10% 16V X7R 3 C300 65L0603104 12 0.1UF +-10% 16V X7R 3 C301 65L0603104 12 0.1UF +-10% 16V X7R 3 C302 65L0603104 12 0.1UF +-10% 16V X7R...
  • Page 48 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 C258 67L 312101 3 SMD 100UF +-20% 16V 3 C259 67L 312101 3 SMD 100UF +-20% 16V 3 C324 67L 312101 3 SMD 100UF +-20% 16V 3 C325...
  • Page 49 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A POWER MLL5232B BY FULL 3 ZD106 93L 39149 POWER MLL5232B BY FULL 3 ZD107 93L 39149 POWER MLL5232B BY FULL 3 ZD108 93L 39149 POWER MLL5232B BY FULL...
  • Page 50 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A LOW ESR 150UF 25V 2 C223 67L215C151 4H 8*7MM 2 L101 71L 55 28 FERRITE BEAD 7.62*5.08* 2 L102 73L 253138 L CHOKE BY LI TAI 2 L201...
  • Page 51 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 Q211 57L 761 2 2SC5706-TL-SMT 3 Q212 57L 761 2 2SC5706-TL-SMT 3 Q209 57L 761 3 2SC5824R SMT 3 Q210 57L 761 3 2SC5824R SMT 3 Q211...
  • Page 52 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 3 R237 61L0603561 CHIP 560 OHM 1/16W 3 R234 61L0603681 CHIP 680 OHM 1/16W 3 R235 61L0603681 CHIP 680 OHM 1/16W 3 R232 61L1206102 CHIP 1K OHM 5% 1/8W...
  • Page 53 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A ADAPTOR BY YAO SHENG 3 PT202 80LL17T 3 YS 3 F101 84L 52 5 CHIP FUSE 6.5A GET-HAND 3 D207 93L 6432U MLL4148 SMD 3 D208 93L 6432U...
  • Page 54 Service Manual Rev: A All manuals and user guides at all-guides.com LM721A 2 SW103 77L 600 1GHJ KEY SWITCH 2 SW104 77L 600 1GHJ KEY SWITCH 2 SW105 77L 600 1GHJ KEY SWITCH 2 DP101 81L 12 1 GP 715L 982 1 S...

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