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HP L1940T Series Service Manual

19” lcd monitor
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HP L1940T

SERVICE MANUAL

19" LCD Monitor
L1940T Series
THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY. EVERY REASONABLE
EFFORT HAS BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL; WE CANNOT GUARANTEE THE
ACCURACY OF THIS INFORMATION AFTER THE DATE OF PUBLICATION AND DISCLAIMS RELIABILITY FOR
CHANGES, ERRORS OR OMISSIONS.
1

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Summary of Contents for HP L1940T Series

  • Page 1: Service Manual

    HP L1940T SERVICE MANUAL 19” LCD Monitor L1940T Series THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY. EVERY REASONABLE EFFORT HAS BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL; WE CANNOT GUARANTEE THE ACCURACY OF THIS INFORMATION AFTER THE DATE OF PUBLICATION AND DISCLAIMS RELIABILITY FOR...

  • Page 2: Table Of Contents

    HP L1940T Table of Contents Table of Contents ------------------------------------------------------------------------------------------------------------------------ 02 Revision List ------------------------------------------------------------------------------------------------------------------------------ 03 1.Monitor Specification ----------------------------------------------------------------------------------------------------------------04 2.LCD Monitor Description ------------------------------------------------------------------------------------------------------------05 3.Operation Instructions ---------------------------------------------------------------------------------------------------------------05 3.1 General Instructions ---------------------------------------------------------------------------------------------------------------05 3.2 Control Button ---------------------------------------------------------------------------------------------------------------------06 3.3 Adjusting The Picture --------------------------------------------------------------------------------------------------------------06 4. Input/Output Specification -------------------------------------------------------------------------------------------------------- 09 4.1 Input Signal Connector -----------------------------------------------------------------------------------------------------------09...

  • Page 3: Revision List

    HP L1940T Revision List Revision Date Revision History TPV Model Feb.-24-06 Initial release T981KMVDBHHPNP...

  • Page 4: Monitor Specification

    HP L1940T 1.Monitor Specifications Driving system TFT Color LCD Panel M190E5-L0A Active Area 376.32(H) x 301.056(V) (19.0") Pixel pitch 0.294( H )x 0.294mm( V ) LCD Panel Viewing Angles(Min / TYP) H:120/140; V:110/130 Response time (typ.) < 8 ms Brightness...

  • Page 5: Lcd Monitor Description

    HP L1940T 2. LCD Monitor Description The LCD Monitor will contain main board, power board, key board and 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: Control Button

    HP L1940T 3.2 Control Buttons Power Indicator: Green — Power On mode. Orange — Power Saving mode. Blank —Power Off Mode. Auto Adjust : Activates the auto adjustment feature for optimum image. Menu : Opens the ON-Screen Display(OSD) menu. Minus (–) : 1、If OSD is on, press to navigate backward through the OSD menu features and decrease adjustment levels.
  • Page 7 HP L1940T Service Mode Press and hold the “Menu” button, Power off -> on “Power”,then into the service mode, Press “menu” button to bring to OSD menu for confirmation as below: Factory Mode 1、 Turn off monitor. 2、 [ Push “Auto Adjust” and “+ (plus)”and hold them at the same time ]+ [ Press power “Power” button untill comes out “windows screen”...
  • Page 8 HP L1940T Menu icons Control Icon Brightness Contrast Auto Adjustment Image Control Color Custom Color Language Management OSD Control Information Factory Reset Default Video Input Horizontal Position Vertical Position Clock Clock Phase Power Saver Mode Display Power-On Status Display Sleep Timer...

  • Page 9: Input/Output Specification

    HP L1940T 4. Input/Output Specification 4.1 Input Signal Connector Analog Connector Pinout Mnemonic Signal Mnemonic Signal Red Video +5 V +5 V (from PC) Green Video Sync Ground Blue Video None None DDC Data GND / Cable Detect Horizontal Sync...
  • Page 10 HP L1940T DVI-D Digital Connector Pins Pin. Mnemonic Signal Pin. Mnemonic Signal TX 2 - TMDS Negative differential input, channel 2 TX 3 + TMDS Data 3 + TX 2 + TMDS Positive differential input, channel 2 +5V Power SHLD 2 / 4...

  • Page 11: Factory Preset Display Modes

    HP L1940T 4.2 Factory Preset Display Modes Pixel Horz Freq Horz Vert Pixel Clk Preset Vert Freq (Hz) Source Format (KHz) Polarity Polarity (MHz) 640 x 480 31.469 59.940 25.175 640 x 480 37.861 72.809 31.500 VESA 640 x 480 37.500...

  • Page 12: Panel Specification

    HP L1940T 5. Panel Specification 5.1 General Feature - Wide viewing angle. - High contrast ratio - Super fast response time - High color saturation - SXGA (1280 x 1024 pixels) resolution - DE (Data Enable) only mode - LVDS (Low Voltage Differential Signaling) interface...

  • Page 13: Optical Characteristics

    HP L1940T 5.2 Optical Characteristics Test Conditions Optical Specifications...

  • Page 14: Monitor Exploded View

    HP L1940T 6. Monitor Exploded View...

  • Page 15: Repair Flow Chart

    HP L1940T 7. Repair Flow Chart...
  • Page 16 HP L1940T...
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  • Page 18: Troubleshooting

    HP L1940T 8. Troubleshooting Problem Possible Cause Solution Screen is blank. Power cord is disconnected. Connect the power cord. Power switch is turned Off. Turn on the power. Video cable is improperly connected. Connect the video cableproperly. Screen blanking utility is active.

  • Page 19: Block Diagram

    HP L1940T 9. Block Diagram...

  • Page 20: Schematic

    HP L1940T 10. Schematic 10.1 Main Board...
  • Page 21 HP L1940T...
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  • Page 23 HP L1940T...
  • Page 24 HP L1940T...

  • Page 25: Inverter/Power Board

    HP L1940T 10.2 Power Board (include inverter and power) AC/DC Schematic...
  • Page 26 HP L1940T Inverter Schematic...
  • Page 27 HP L1940T AC/DC Function Block Schematic...
  • Page 28 HP L1940T Inverter Function Block Schematic...

  • Page 29: Key Board

    HP L1940T 10.3 Key Board...
  • Page 30 HP L1940T...

  • Page 31: Pcb Layout

    HP L1940T 11. PCB Layout 11.1 Main Board...

  • Page 32: Inverter/Power Board

    HP L1940T 11.2 Inverter / Power Board...

  • Page 33: Key Board

    HP L1940T 11.3 Key Board...

  • Page 34: Maintainability

    HP L1940T 12. Maintainability Equipments and Tools Requirement 1、Multi-meter. 2、Oscilloscope. 3、Pattern Generator. 4、DDC Tool with an IBM Compatible Computer. 5、Alignment Tool. 6、LCD Color Analyzer. 7、Service Manual. 8、User Manual.

  • Page 35: White-Balance,Luminance Adjustment

    = 313±20, y = 329 ±20, Y= 150 cd/m 3. Into factory mode of HP L1940T [ Push “Auto Adjust” and “+ (plus)”and hold them at the same time ]+ [ Press power “Power” button untill comes out “windows screen”...
  • Page 36 HP L1940T 2. The chroma 7120 will show x = 313 ±20, y = 329 ±20, Y = 180 cd/m 3. Switch the chroma 7120 l to RGB MODE ( with press “MODE” button to change ) 4. Adjust the RED of color 6500K on factory window until chroma 7120 indicator reached the value R=100 5.

  • Page 37: Check List After Replacing Lcd Main Board

    HP L1940T 14. Check List after replacing LCD Main board Check if white-balance is within the specs after replacing Main board and panel, then re-writing DDC is necessary. 14.1 Check white-balance The white-balance value for each common color temperature: 9300 º K: x=283± 20 ; y = 297± 20;...
  • Page 38 HP L1940T 2. Select the DDC2Bi as the communication channel. As shown in Fig. 12. 3. Click OK button to confirm your selection. 4. Click icon (Read EDID function) to read DDC EDID data from monitor. The EDID codes will display on screen as...
  • Page 39 HP L1940T Step 3: Modify DDC data (verify EDID version, week, year) Click (new function) icon from the tool bar, bring up Step 1 of 9 as shown in Fig. 14 . EDID4.6 DDC application provides the function selection and text change (select & fill out)from Step 1 to Step 9.
  • Page 40 HP L1940T 2. Click Next , bring up Fig.16. 3. Click Next , bring up Fig.17.
  • Page 41 HP L1940T 4. Click Next , bring up Fig.18. 5. Click Next , bring up Fig.19.
  • Page 42 HP L1940T 6. Click Next , bring up Fig. 20. In this step, please confirm the Descriptor Data Type is Monitor Range Limits, and all the items are same as below. 7. Click Next , bring up Fig. 21.
  • Page 43 HP L1940T 8. Click Next , bring up Fig. 22. - Click Finish to exit the Step window. - Serial number can be filled up at this moment (for example,TWP318Q001). NOTE: You must modify the Serial NO. In step 9, otherwise the Serial NO. In OSD Couldn't be modified correctly.
  • Page 44 HP L1940T 2. Access Factory Mode 1). Turn off monitor. 2). [Push "Auto Adjust " and" +(plus)"and hold them at the same time ] + [Press power "Power " button untill comes out "Windows screen"] => then release all button, then press "Menu" button, wait until the OSD menu with Characters "F"...
  • Page 45 HP L1940T Sometimes, you may need to save DDC data as a text file for using in other IC chip. To save DDC data, follow the steps below: 1. Click (Save) icon (or click "file"-> "save as") from the tool bar and give a file name as shown in Fig. 25. The file type is EDID46 file (*.ddc) which can be open in WordPad.
  • Page 46 HP L1940T Step 2: Read DDC data from monitor 1. Click icon as shown in Fig. 11 from the tool bar to bring up the Channels "Configuration Setup" windows as shown in Fig. 2. Select the DDC2Bi as the communication channel. As shown in Fig. 29.
  • Page 47 HP L1940T 3. Click OK button to confirm your selection. 4. Click icon (Read EDID function) to read DDC EDID data from monitor. The EDID codes will display on screen as shown in Fig. 30. Step 3: Modify DDC data (verify EDID version, week, year) Click (new function) icon from the tool bar, bring up Step 1 of 9 as shown in Fig.
  • Page 48 HP L1940T 2. Click Next , bring up Fig. 33. Fig. 33 Fig. 34 3. Click Next , bring up Fig. 34. 4. Click Next , bring up Fig. 35. 5. Click Next , bring up Fig. 36. 6. Click Next , bring up Fig. 37.
  • Page 49 HP L1940T 8. Click Next , bring up Fig. 39. - Click Finish to exit the Step window. - Serial number can be filled up at this moment (for example, TWP318Q001). NOTE: You must modify the Serial NO. In step 9, otherwise the Serial NO. In OSD Couldn't be modified correctly.
  • Page 50 HP L1940T 3) Push Menu to exit OSD menu. 3. Click (Write EDID) icon from the tool bar to write DDC data.Then the screen will be black for 5-10 seconds, when the screen recovers ,DDC data will be finished Writing.
  • Page 51 HP L1940T 1. Click (Save) icon (or click "file"-> "save as") from the tool bar and give a file name as shown in Fig. 46. The file type is EDID46 file (*.ddc) which can be open in WordPad. By using WordPad, the texts of DDC data & table (128 bytes, hex code) can be modified.

  • Page 52: Edid Content

    HP L1940T 15. EDID Content Analog 16 : 32 : 48 : 64 : 80 : 96 : 112: Digital 16 : 32 : 48 : 64 : 80 : 96 : 112:...

  • Page 53: Bom List

    Part No. for TPV Description Quantity Unit 007G 7 L151 COMPOUND PALLET 0.025 015G6344 1 AC BRACKET 1.000 023G3178690 7A HP LOGO 7121-8115 1.000 034G6402 EY B REAR COVER 1.000 037G6057 2 HINGE 1.000 040G 152509 RECYCLE LABEL 1.000 040G 152512 RECYCLE LABEL 1.000...
  • Page 54 HP L1940T 8161 095G8P14 7505 CBLE-267 7/330/7-267 AWG28 1.000 8161 095G8P14 7505 CBLE-267 7/330/7-267 AWG28 1.000 0M1G 130 4225 SCREW 4.000 0M1G1340 10 47 SCREW M4X10 BLK 4.000 0M1G1430 5128 SCREW (FOR SHIELD) 1.000 0M1G1430 5128 SCREW (FOR SHIELD) 4.000 0M1G1640 8120 SCREW PHM4-0.7X8...
  • Page 55 HP L1940T 1603 088G 350 1 TN USB CONN 1.000 1602 088G 351 2B CL USB CONN 1.000 1602 088G 351 2B TN USB CONN 1.000 1203 088G 35315F H D-SUB 15PIN 1.000 1203 088G 35315F HJ SOC SUBD H 15P F 1.000...
  • Page 56 HP L1940T 3634 061L0603000 RST SM 0603 JUMP MAX 0R05 R 1.000 3614 061L0603000 RST SM 0603 JUMP MAX 0R05 R 1.000 3606 061L0603000 RST SM 0603 JUMP MAX 0R05 R 1.000 3605 061L0603000 RST SM 0603 JUMP MAX 0R05 R 1.000...
  • Page 57 HP L1940T 3512 061L0603103 CHIPR 10K OHM +-5% 1/16W 1.000 3522 061L0603103 CHIPR 10K OHM +-5% 1/16W 1.000 3523 061L0603103 CHIPR 10K OHM +-5% 1/16W 1.000 3617 061L0603103 CHIPR 10K OHM +-5% 1/16W 1.000 3608 061L0603103 CHIPR 10K OHM +-5% 1/16W 1.000...
  • Page 58 HP L1940T 3642 061L0603330 9F rst sm 0603 rc22h 33r pm1 r 1.000 3633 061L0603330 9F rst sm 0603 rc22h 33r pm1 r 1.000 3630 061L0603330 9F rst sm 0603 rc22h 33r pm1 r 1.000 3502 061L0603470 CHIPR 47 OHM +-5% 1/16W 1.000...
  • Page 59 HP L1940T 2441 065G0603104 12 CER2 0603 X7R 16V 100N PM10 R 1.000 2440 065G0603104 12 CER2 0603 X7R 16V 100N PM10 R 1.000 2438 065G0603104 12 CER2 0603 X7R 16V 100N PM10 R 1.000 2436 065G0603104 12 CER2 0603 X7R 16V 100N PM10 R 1.000...
  • Page 60 HP L1940T 2202 065G0603104 12 CER2 0603 X7R 16V 100N PM10 R 1.000 2201 065G0603104 12 CER2 0603 X7R 16V 100N PM10 R 1.000 2433 065G0603104 12 CER2 0603 X7R 16V 100N PM10 R 1.000 2432 065G0603104 12 CER2 0603 X7R 16V 100N PM10 R 1.000...
  • Page 61 HP L1940T 2435 067G 312100 3T SMD 10uf +-20% 16V 1.000 2435 067G 312100 3T SMD 10uf +-20% 16V 1.000 2437 067G 312100 3T SMD 10uf +-20% 16V 1.000 2437 067G 312100 3T SMD 10uf +-20% 16V 1.000 2437 067G 312100 3T SMD 10uf +-20% 16V 1.000...
  • Page 62 HP L1940T 5605 071GP57K101 TA IND FXD 1206 EMI 100MHZ 100R R 1.000 5606 071GP57K101 TA IND FXD 1206 EMI 100MHZ 100R R 1.000 5607 071GP57K101 TA IND FXD 1206 EMI 100MHZ 100R R 1.000 5601 071GP57K101 TA IND FXD 1206 EMI 100MHZ 100R R 1.000...
  • Page 63 HP L1940T 6207 093G 64 33 DIO SIG SM BAV99 (PHSE)R 1.000 6207 093G 64 33 DIO SIG SM BAV99 (PHSE)R 1.000 6207 093G 64 33 DIO SIG SM BAV99 (PHSE)R 1.000 6208 093G 64 33 DIO SIG SM BAV99 (PHSE)R 1.000...
  • Page 64 HP L1940T 1936 077G 604 1 FD SWI TACT 1P 1POS 12V V 1MM5 R 1.000 6931 081G 14500 KB LED VS SM KAA-3528YSGC (KIEL)R 1.000 715G1855 1 KEY BOARD 1.000...
  • Page 65 文件名: AOC Service Manual-HP L1940T (GM5321) 目录: D:\Service Manual\LCD\HP\AOC Service Manual- HP L1940T 模板: C:\Documents and Settings\qiufen.mao\Application Data\Microsoft\Templates\Normal.dotm 标题: 主题: 作者: 关键词: 备注: 创建日期: 2005-12-26 10:33:00 修订号: 上次保存日期: 2008-1-24 10:34:00 上次保存者: Administrator 编辑时间总计: 743 分钟 上次打印时间: 2008-1-24 10:39:00 打印最终结果 页数:...
  • Page 66 字数: 7,349 (约) 字符数: 41,893 (约)

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