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Kobian 1990TWA Service Manual

19"w lcd color monitor
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19"W LCD Color Monitor
Service
Service
Service
Description
Table Of Contents..........................................................1
Revision List.............................................................2
Important Safety Notice.............................................3
1. Monitor Specification...............................................4
2. LCD Monitor Description........................................5
3. Operation Instructions............................................6
3.1 Control Buttons......................................................6
3.2 Attaching the Cables...............................................7
3.3 Adjusting the Picture..........................................7
4. Input/Output Specification.......................................10
4.1 Input Signal Connector...........................................10
N
4.2 Factory Preset Display Modes...........................10
4.3 Panel Specification.........................................11
5. Block Diagram.....................................................15
5.1 Software Flow Chart............................................15
ANY PERSON ATTEMPTING TO SERVICE THIS CHASSIS MUST FAMILIARIZE HIMSELF WITH THE
CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS TO BE USED WHEN SERVICING
ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.
CAUTION: USE A SEPARATE ISOLATION TRANSFOMER FOR THIS UNIT WHEN SERVICING

TABLE OF CONTENTS

Page
Description
5.2 Electrical Block Diagram...................................17
6.Schematic......................................................19
6.1 Main Board..........................................................19
6.2 Power Board.....................................................24
6.3 Key Board.........................................................27
7.PCB Layout...........................................................28
7.1 Main Board........................................................28
7.2 Power Board.................................................29
7.3 Key Board...................................................30
8. Maintainability................................................31
8.2 Trouble Shooting................................................31
10. Monitor Exploded View.....................................39
11. BOM List..............................................................40
SAFETY NOTICE
1
KOBIAN 1990TWA
Horizontal Frequency
30kHz - 83kHz
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Summary of Contents for Kobian 1990TWA

  • Page 1: Table Of Contents

    19”W LCD Color Monitor KOBIAN 1990TWA Service Service Service Horizontal Frequency 30kHz – 83kHz TABLE OF CONTENTS Description Page Description Page 5.2 Electrical Block Diagram….…...………..…..…...17 Table Of Contents..……..……......…..1 6.Schematic……………........…19 Revision List.….....……......……..2 6.1 Main Board.……...……..........19 Important Safety Notice.…………....……..3 6.2 Power Board..………..……........24 1.

  • Page 2: Revision List

    19”W LCD Color Monitor KOBIAN 1990TWA Revision List Revision Date Revision History TPV Model Dec.-10-08 Initial Release T98SM5NCWWKBAN...

  • Page 3: Important Safety Notice

    19”W LCD Color Monitor KOBIAN 1990TWA Important Safety Notice Proper service and repair is important to the safe, reliable operation of all AOC Company Equipment. The service procedures recommended by AOC and described in this service manual are effective methods of performing service operations.

  • Page 4: Monitor Specification

    19”W LCD Color Monitor KOBIAN 1990TWA 1. Monitor Specifications Driving system 19" wide TFT Color LCD Viewable Image Size 481mm diagonal LCD Panel Pixel pitch 0.2835mm( H ) × 0.2835mm( V ) Video R,G,B Analog Interface Separate Sync. H/V TTL H-Frequency 30kHz –...

  • Page 5: Lcd Monitor Description

    19”W LCD Color Monitor KOBIAN 1990TWA 2. LCD Monitor Description The LCD monitor will contain a main board, a power board and a key board which house the flat panel control logic, brightness control logic and DDC. The power board will provide AC to DC Inverter voltage to drive the backlight of panel and the main board chips each voltage.

  • Page 6: Operation Instructions

    19”W LCD Color Monitor KOBIAN 1990TWA 3. Operating Instructions 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 7: Attaching The Cables

    19”W LCD Color Monitor KOBIAN 1990TWA OSD Lock Function: To lock the OSD, press and hold the MENU button while the monitor is off and then press power button to turn the monitor on. To un-lock the OSD - press and hold the MENU button while the monitor is off and then press power button to turn the monitor on.
  • Page 8 19”W LCD Color Monitor KOBIAN 1990TWA The OSD Message Main Main Menu Sub Menu Sub Menu Menu Description Item Item Icon Icon Brightness Backlight Adjustment Contrast Contrast from Digital-register. Standard Standard Mode Text Text Mode Internet Internet Mode Game Game Mode...
  • Page 9 19”W LCD Color Monitor KOBIAN 1990TWA Main Main Menu Sub Menu Sub Menu Menu Description Item Item Icon Icon Warm Recall Warm Color Temperature from EEPROM. Normal Recall Normal Color Temperature from EEPROM. Cool Recall Cool Color Temperature from EEPROM.

  • Page 10: Input/Output Specification

    19”W LCD Color Monitor KOBIAN 1990TWA 4. Input/Output Specification 4.1 Input Signal Connector Pin No. Description Pin No. Description Green Ground Blue Ground Ground DDC-Serial Data Detect Cable H-Sync R-Ground V-Sync G-Ground DDC-Serial Clock B-Ground 15 - Pin Color Display Signal Cable 4.2 Factory Preset Display Modes...

  • Page 11: Panel Specification

    19”W LCD Color Monitor KOBIAN 1990TWA 4.3 Panel Specification LTM190M2-L31 is a color active matrix liquid crystal display(LCD) that uses amorphous silicon TFT(Thin Film Transistor) as switching components. This model is composed of a TFT LCD panel, a driver circuit and a back light unit.
  • Page 12 19”W LCD Color Monitor KOBIAN 1990TWA 4.3.2 Optical Characteristics...
  • Page 13 19”W LCD Color Monitor KOBIAN 1990TWA 4.3.3 Electrical Characteristics TFT LCD Module:...
  • Page 14 19”W LCD Color Monitor KOBIAN 1990TWA Back Light Unit:...

  • Page 15: Block Diagram

    19”W LCD Color Monitor KOBIAN 1990TWA 5. Block Diagram 5.1 Software Flow Chart...
  • Page 16 19”W LCD Color Monitor KOBIAN 1990TWA Remark: 1) MCU initializes. 2) Is the EPROM blank? 3) Program the EPROM by default values. 4) Get the PWM value of brightness from EPROM. 5) Is the power key pressed? 6) Clear all global flags.

  • Page 17: Electrical Block Diagram

    19”W LCD Color Monitor KOBIAN 1990TWA 5.2 Electrical Block Diagram 5.2.1 Main Board Panel Interface Crystal 14.318MHZ (CN403) (X401) Scalar TSUM1PFR-LF FLASH ROM Key Control SST25LF020A Interface (Include ADC, OSD, MCU) (U402) (CN401) (U401) D-Sub Connector (CN101)
  • Page 18 19”W LCD Color Monitor KOBIAN 1990TWA 5.2.2 Power Board AC input 100V~240V Main Output Transformer VEMI filter Rectifier Board/Inverter Rectifier Circuit Power Switching IC Power Supply PWM Control IC Sense Resistor Sampling Photo Couple Transformer High Voltage Output Switching MOS...

  • Page 19: Schematic

    19”W LCD Color Monitor KOBIAN 1990TWA 6. Schematic 6.1 Main Board 715G2904 1 TSUM1PFR SCHEMATIC XGA/SXGA LVDS OUTPUT DSUB_R+ DSUB_R+ VCC1.8 DSUB_R- DSUB_R- DSUB_G+ DSUB_G+ VCC3.3 DSUB_G- DSUB_G- VCC1.8 DSUB_SOG DSUB_SOG CMVCC DSUB_B+ DSUB_B+ DSUB_5V DSUB_B- DSUB_B- VCC3.3 CMVCC1 DSUB_H...
  • Page 20 19”W LCD Color Monitor KOBIAN 1990TWA H_Sy nc R101 0R05 1/10W 5% R102 100R 1/16W 5% DSUB_H V_Sy nc R103 100R 1/16W 5% FB102 DSUB_V R104 C101 VGA_B+ DSUB_B+ VCC3.3 R105 R106 C102 C103 BEAD 2K2 1/16W 5% 2K2 1/16W 5% 100R 1/16W 5% 0.047uF...
  • Page 21 19”W LCD Color Monitor KOBIAN 1990TWA AVDD VDDP VDDC VCC3.3 VDDP AVDD FB401 U401 VCC3.3 300OHM VCTRL VCTRL C403 C404 LVA3P 0.1uF/16V 0.1uF/16V DSUB_R+ RIN0P LVA3M DSUB_R- RIN0M PA[0..1] DSUB_G+ GIN0P PA[0..1] DSUB_G- GIN0M LVA2P DSUB_SOG SOGIN0 LVA2M DSUB_B+ BIN0P...
  • Page 22 19”W LCD Color Monitor KOBIAN 1990TWA PANEL_VCC CN403 PA[0..1] PB[0..9] PA[0..1] PB[0..9] R434 C420 PA[4..9] PA[4..9] 330 OHM 1/4W 0.1uF/16V CMVCC AO3401L CMVCC R433 C419 R435 10K 1/16W 5% 0.1uF/16V PANEL_VCC 4K7 1/16W 5% Q405 AO3401 R436 FB402 CONN 100K 1/16W 5%...
  • Page 23 19”W LCD Color Monitor KOBIAN 1990TWA ESD_VCC 2 DSUB_5V CMVCC DSUB_5V 2 5, 6 CMVCC VCC3.3 VCC3.3 D403 D401 BAT54C NC/BAV99 CN404 VCC3.3 R437 R439 CMVCC1 SM340A D402 10K 1/16W 5% 10K 1/16W 5% CMVCC CMVCC1 CMVCC BKLT-EN VCC1.8 Q410...

  • Page 24: Power Board

    19”W LCD Color Monitor KOBIAN 1990TWA 6.2 Power Board 715G2824 2 2 D909 NC/31DQ10FC R918 L904 100 OHM 1/4W 2A(INVERTER) R919 100 OHM 1/4W +16V FB904 C912 R920 BEAD 0.001uF ZD902 100 OHM 1/4W R946 RLZ18B 150 OHM 2W C917...
  • Page 25 19”W LCD Color Monitor KOBIAN 1990TWA CN801 CONN T801 R801 0R05 1/8W C801 18pF/6KV L801 +16V NC / L R802 CN802 100R 1/8W C825 CONN 18pF/6KV R804 0R05 1/8W R805 NC/4K7 1/10W 5% R810 Q802 R808 Q801 R850 15R 1/4W 5%...
  • Page 26 19”W LCD Color Monitor KOBIAN 1990TWA +5V1 +5V1 C604 C602 C603 R602 0.47uF/16V 100uF/25V 0.47uF/16V 10K 1/10W 5% R603 10K 1/10W 5% C609 1uF/25V 10K 1/10W 5% CN602 R609 IC601 IC APA2069 LOUT- WAFER 2.0MM 4P R604 SE/BTL LOUT- CN601...

  • Page 27: Key Board

    19”W LCD Color Monitor KOBIAN 1990TWA 6.3 Key Board 715G2835 1 LED_RED# LED_GRN# LED001 CN001 LBADC1 R002 2K OHM 1/4W LBADC2 DC_POWERON R003 0R05 1/10W 1% LED_GRN# LED_RED# C001 C002 C003 C004 C005 R004 2K OHM 1/4W R005 1K 1/10W 1% NC/0.001uF...

  • Page 28: Pcb Layout

    19”W LCD Color Monitor KOBIAN 1990TWA 7. PCB Layout 7.1 Main Board 715G2904 1...

  • Page 29: Power Board

    19”W LCD Color Monitor KOBIAN 1990TWA 7.2 Power Board 715G2824 2 2...

  • Page 30: Key Board

    19”W LCD Color Monitor KOBIAN 1990TWA 7.3 Key Board 715G2835 1...

  • Page 31: Maintainability

    19”W LCD Color Monitor KOBIAN 1990TWA 8. Maintainability 8.1 Equipments and Tools Requirement Voltmeter. Oscilloscope. Pattern Generator. DDC Tool with an IBM Compatible Computer. Alignment Tool. LCD Color Analyzer. Service Manual. User Manual. 8.2 Trouble Shooting 8.2.1 Main Board No power...
  • Page 32 19”W LCD Color Monitor KOBIAN 1990TWA No picture (LED orange) No picture The button if under X401 oscillate Replace X401 waveform is normal control Check reset circuit of Check Correspondent component U401 is normal Check C423(+) =1.8V; U404 Vout=3.3V Replace U401...
  • Page 33 19”W LCD Color Monitor KOBIAN 1990TWA White screen White screen Measure Q404 base X401 oscillate waveform is normal is low level? Replace X401 Check CN403 is solder Check reset circuit of and Q405 is OK U401 is normal Check Correspondent Check Correspondent component.
  • Page 34 19”W LCD Color Monitor KOBIAN 1990TWA 8.2.2 Power Board No power Check AC line volt 110V or 220V Check AC input Check the voltage of C905 (+) Check bridge rectified circuit and F901 circuit Check start voltage for the pin3 of U901...
  • Page 35 19”W LCD Color Monitor KOBIAN 1990TWA No backlight Check C802=16V Check adapter Check ON/OFF signal Check main board Check U801 PIN12=16V Change ON/OFF circuit Check U801 PIN5 have triangle wave Change U801 Check U801 PIN9/PIN10 PWM wave Check U801 Check Q804, Q809 Drain wave...
  • Page 36 19”W LCD Color Monitor KOBIAN 1990TWA 8.2.3 Key Board OSD is unstable or not working Connect Key Pad Board Is Key Pad Board connecting normally? Replace Button Switch Is Button Switch normally? Replace Key Pad Board Is Key Pad Board Normally?

  • Page 37: White-Balance, Luminance Adjustment

    19”W LCD Color Monitor KOBIAN 1990TWA 9. White-Balance, Luminance Adjustment Approximately 30 minutes should be allowed for warm up before proceeding White-Balance adjustment. 1. How to do the Chroma-7120 MEM. Channel setting A. Reference to chroma 7120 user guide B. Use “SC” key and “NEXT” key to modify x,y,Y value and use “ID” key to modify the TEXT description.
  • Page 38 19”W LCD Color Monitor KOBIAN 1990TWA 5. Adjust the GREEN on factory window until chroma 7120 indicator reached the value G=100 6. Adjust the BLUE on factory window until chroma 7120 indicator reached the value B=100 7. Repeat above procedure (item 4, 5, 6) until chroma 7120 RGB value meet the tolerance =100±2 D.

  • Page 39: Monitor Exploded View

    19”W LCD Color Monitor KOBIAN 1990TWA 10. Monitor Exploded View...

  • Page 40: Bom List

    19”W LCD Color Monitor KOBIAN 1990TWA 11. BOM List T98SM5NCWWKBAN Location Part No. Description Remark 050G 600 2 HANDLE1 050G 600 3 HANDLE2 052G 1150 C INSULATING TAPE 052G 1185 1 BIG TAPE 052G 1186 SMALL TAPE 052G 1207 A CONDUCTIVE TAPE 45MM *25MM *0.08MM...
  • Page 41 19”W LCD Color Monitor KOBIAN 1990TWA Q409 057G 417 22 T TRA KN2907AS -60V/-0.6A SOT-23 Q410 057G 417 22 T TRA KN2907AS -60V/-0.6A SOT-23 Q405 057G 763 1 A03401 SOT23 BY AOS(A1) R401 061G0402000 RST CHIP MAX 0R05 1/16W R402...
  • Page 42 19”W LCD Color Monitor KOBIAN 1990TWA R448 061G0402472 RST CHIPR 4.7 KOHM +-5% 1/16W R107 061G0402750 RST CHIPR 75 OHM +-5% 1/16W R112 061G0402750 RST CHIPR 75 OHM +-5% 1/16W R116 061G0402750 RST CHIPR 75 OHM +-5% 1/16W R101 061G0603000...
  • Page 43 19”W LCD Color Monitor KOBIAN 1990TWA SW003 077G 600 1GCJ TACT SWITCH TSPB-2 -NP SW004 077G 600 1GCJ TACT SWITCH TSPB-2 -NP SW005 077G 600 1GCJ TACT SWITCH TSPB-2 -NP SW001 077G 600 1A CJ TACT SWITCH 2PIN SW002 077G 600 1A CJ...
  • Page 44 19”W LCD Color Monitor KOBIAN 1990TWA CN901 087G 501 32 S AC SOCKET CN601 088G 30214K DC PHONE JACK 5PIN BD901A 093G 50460 28 BRIDGE DIODE KBP208G LITEON D907 093G3006 1 1 31DQ06FC3 NIHON INTER CN902 095G 82014W510 WIRE HARNESS 14P(SAN)-9(PH)
  • Page 45 19”W LCD Color Monitor KOBIAN 1990TWA R819 061G0603100 2F RST CHIPR 10K OHM +-1% 1/10W R808 061G0603100 2F RST CHIPR 10K OHM +-1% 1/10W R813 061G0603101 RST CHIPR 100 OHM +-5% 1/10W R604 061G0603103 RST CHIPR 10 KOHM +-5% 1/10W...
  • Page 46 19”W LCD Color Monitor KOBIAN 1990TWA R938 061G0805103 RST CHIPR 10K OHM +-5% 1/8W R843 061G0805105 RST CHIPR 1M OHM +-5% 1/8W R924 061G0805151 RST CHIPR 150 OHM +-5% 1/8W R826 061G0805180 3F RST CHIPR 180 KOHM +-1% 1/8W R943...
  • Page 47 19”W LCD Color Monitor KOBIAN 1990TWA C815 065G0603222 22 CHIP 2200PF 25V X7R C817 065G0603222 22 CHIP 2200PF 25V X7R C818 065G0603222 22 CHIP 2200PF 25V X7R C601 065G0603474 12 MLCC 0603 0.47UF K 16V X7R C602 065G0603474 12 MLCC 0603 0.47UF K 16V X7R...
  • Page 48 19”W LCD Color Monitor KOBIAN 1990TWA R946 061G152M47152T RST MOFR 470 OHM +-5% 2WS C906 065G 2K152 1T6213 CAP CER 1500PF K 2KV C604 067G215Y1014KT EC CAP.105℃ C908 067G215Y2207KT CAP 105℃ 22UF M 50V KINGNICHI C605 067G215Y2207KT CAP 105℃ 22UF M 50V KINGNICHI...
  • Page 49 Q33G0171 1 1C0100 LENS Q34G0264ABJA2B0130 BEZEL(L19WA-8Q2) Q34G0265ABJA8B0100 REAR COVER19" Q40G 19N011 1B RATING LABEL Q44G9123011 1B 19 LCD KOBIAN CARTON Q44G9123101 EPS_L19WQ Q44G9123201 Q45G 77 5 PE PACKING Q45G 88607 28 PE BAG FOR CLAMP/STAND Q45G 88607 34 PE BAG FOR BASE...

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