HP WF1907 Service Manual
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HP WF1907 Service Manual

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See also: Service Manual , User Manual
HP
Service
Service Manual
01.
02.
03.
04.
05.
Any person attempting to service this chassis must familarize with the chassis and be aware of the necessary safety
precautions to be used when serving electronic equipment containing high voltage.
Published by LITE-ON Service

Table of Contents

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Safety Notice
Printed in Taiwan
HP_LCD_W1907&WF1907_SM061031V00
HP
WF
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©
All rights reserved
Subject to modification 31th Oct-2006
1907 & W1907
June.19th-2006

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  • Page 1: Table Of Contents

    HP_LCD_W1907&WF1907_SM061031V00 Service 1907 & W1907 Service Manual June.19th-2006 Table of Contents Power Board Operation Theory ----------------------------------------------------------------01 Inverter Circuit --------------------------------------------------------------------------------------02 Interface Operation --------------------------------------------------------------------------------03 Troubleshooting ------------------------------------------------------------------------------------10 Schematic -------------------------------------------------------------------------------------------24 Safety Notice Any person attempting to service this chassis must familarize with the chassis and be aware of the necessary safety precautions to be used when serving electronic equipment containing high voltage.
  • Page 2 HP W1907& WF1907 Service Manual 1. Power Board Operation Theory 1.1 Line filter consists of C801, T801, C802, C803, C804, C808, C809, C815, C819, C820, C825. It eliminates high frequency interference to meet EMI’s requirement. 1.2 Rec & Filter Bridge diode D812, D813, D814, D815 converts AC source into pulsed DC. This pulsed DC is smoothed and filtered by C805.

  • Page 3: Power Board Operation Theory

    2. Inverter Circuit This unit operates on an output voltage of 22V from power source. 2.1 VDD: R105 get a +5VDC for I101 power supply. 2.2 Control IC: I101 (OZ9938) 2.2.1 Enable : When pin 1 of I101 is over 2V, I101 works. If it is under 1V, I101 turns off. 2.2.2 OSC: When I101 enabled, C104/R118/R107 (pin 13 of I101) determine the operating frequency.

  • Page 4: Interface Operation

    3. Interface Operation 3.1 Top (Circuit diagrams sheet 2 of 8) This page is function block. (1) Power. (2) VGA & DDC interface. (3) DVI & DDC interface. (4) Scaler Gm5726H (Gm5766H). (5) Key & panel interface. (6) Audio. 3.2 Power (Circuit diagrams sheet 3 of 8) 3.2.1 P301 connector A 5V power supply for LCD module, also it is main power of interface board.
  • Page 5 3.2.6 Q301, R301, R302, R304 : Adjust back light luminance of LCD module It is adjusted back light luminance control (BKLT_ADJ) is performed for the back light luminance. The BKLT_ADJ signal is generated from I306 scaler IC Gm5726H (Gm5766H). 3.3 VGA & DDC interface (Circuit diagrams sheet 4 of 8) This sheet has RGB analog video and H/V sync signals input from VGA connector.
  • Page 6 3.5.1 I308 EEPROM (24LC16B) The control data and parameter, and OSD related setting, and other service data, to be stored in I308. The contents of which are updated as required. 3.5.2 I309 SPI Flash ROM The firmware program running from I309 external SPI flash ROM, contains firmware code and data for all firmware function.
  • Page 7 The P309 is audio signal input from the audio source. 3.7.2 P310 connector The P310 is audio output to speaker and support 2W x 2 speakers. 3.7.3 I310 TPA6021A4 The I310 is 2x2W stereo audio amplifier, it is an integrated class-AB dual output amplifier. 3.7.4 Q309 : Power down and mute control for Audio ON/OFF control (AUDIO_EN) is performed for standby mode and mute function.
  • Page 8 (Gm5766H). Table 2 video mode Polarity Mode Resolution H-Freq (KHz) Band Width (MHz) 640x480 (59.94Hz) 31.469 25.175 640x480 (72Hz) 37.861 31.5 640x480 (75Hz) 37.5 31.5 720x400 (70Hz) 31.469 28.322 800x600 (60Hz) 37.879 800x600 (72Hz) 48.077 800x600 (75Hz) 46.875 49.5 832x624 (74.55Hz) 49.722 57.284 1024x768 (60Hz)
  • Page 9 supplies according to the sequence show below. Power Key 296ms LED Blue 516ms PANELVCC_E 825ms BKLT_EN 3.68s AUDIO_EN 3.8.4 Power OFF sequence When the POWER key switch is pressed, while the power supply is ON, the POWER key switch signal is turned “H”. When this “H” potential is detected, the CPU begins to turn off the respective power supplies according to sequence show below.
  • Page 10 3.8.5 List of I/O Pin Assignments of the I306 Pin No. Port Signal Name Initial Setting Function LBADC_IN3 PWR_KEYn ON/OFF LCD monitor GPIO14 LED_B LED Blue enable when is H GPIO13 LED_A LED amber enable when is H LBADC_IN2 KEY_UPn OSD up/plus enable when is 2.46V LBADC_IN1 KEY_MENUn OSD enter enable when is 2.46V...

  • Page 11: Troubleshooting

    4. Troubleshooting 4.1 No.display of screen (Screen is black, color of LED is amber) Does OSD display when you push MENU button. Proceed "No OSD display" section. When a signal isn't being input, it is indicated with "VIDEO INPUT". it is indicated with "OUT OF RANGE"...
  • Page 12 4.2 Nothing display on screen screen is black, color of LED is blue Is backlight light up? Refer "Checking the backlight unit" section” Does computer output RGB video signals? Check the video cable for failure. Check the host for output signal with all (VGA or DVI) black only.
  • Page 13 Continue Check the 3.3V power are supplied on I302 pin 2, 4. Check if the voltage on I302 pin 3 that is power DC at 5V. Failure Point 1) Printed wire broke between P301 pin 5, 6 and I302. 2) FB301, FB302 are open. 3) Check power board.
  • Page 14 Continue Check the 5V power are supplied on P306 pin 1, 2, 3 (to the LCD panel) Check if the Voltage on I301 pin 2 that is DC power at 5V. Failure Point 1) Printed wire broke between P301 pin 5, 6, and I301 pin 2.

  • Page 15: Checking The Back Light Unit

    4.3 Checking the back light unit Is +20V supplied to inverter PWB ? (by the power board) Failure Point 1) Inverter cable disconnection. 2) Power board failure. Check the BACKLIGHT_EN signal of the P301 pin 2 at high level. Failure Point 1) printed wire broke between P301 pin 2, R305 and I306 pin 49.

  • Page 16: Abnormal Screen

    4.4 Abnormal screen 4.4.1 Abnormal screen for VGA source Check the R, G, B video signal from computer input on P302 of video connector. Failure Point 1) No R, G, B video signals output from host computer, check computer. 2) VGA video signal cable disconnection. Check the R, G, B input video signals on I306 pin 99, 96, 93 respectively that their level is 0.5 to 1.0Vp-p.
  • Page 17 Failure Point Check the HP output signal to P303 pin 16 respectively that voltage is 4.0 to 5 V. The HP is high will to generated TMDS from PC host. 1) Check P303 pin 14 if is 5V. 2) Printed wire broke between P303 pin 14 and Q305.
  • Page 18 4.5 Abnormal OSD display adjust problem Check the input level whether was changed when pressed function keys on the P308 pin 2, 3, 4, 5. (normal is 3.3V, when push button, generated different voltage. pin 2, 4 is 2.46V, pin 3, 5 is 2V) Failure Point 1) Function key wire disconnection.

  • Page 19: Abnormal Plug And Play Operation

    4.6 Abnormal plug and play operation 4.6.1 Abnormal plug and play operation for VGA Confirm the host computer supplies DDC/CI mode. Failure Point The host machine is not communicated in DDC/CI mode. Check the voltage on P302 pin 9 that is DC 5 V. Failure Point The VGA video cable is failure.
  • Page 20 4.6.2 Abnormal plug and play operation for DVI Confirm the host computer supplies DDC/CI mode. Failure Point The host machine is not communicated in DDC/CI mode. Check the voltage on P303 pin 14 that is DC 5 V. Failure Point The DVI-D video cable is failure.

  • Page 21: Checking The Interface Circuit Of Sync Signal

    4.7 Checking the interface circuit of sync signal 4.7.1 Checking the control circuit of horizontal sync pluse for VGA Check the horizontal sync signal on P302 pin 13 TTL level. Failure Point VGA Video cable is failure. Check the horizontal sync signal on I306 pin 89 TTL level.

  • Page 22: Checking The Resolution Change Ic Movement

    4.8 Checking the resolution change IC movement Check +3.3V supply on I306 pin 110, 101, 92, 82, 74, 2, 25,47, 53, 91, 116, 63. Proceed " Checking the DC/DC converter circuit" section. Check +1.8V supply on I306 pin 118, 87, 55, 17, 78, 70, 104, 106. Proceed "...

  • Page 23: Audio No Signal Output

    4.9 Audio No Signal Output Check the audio signal input from the audio source. Failure Point 1) No audio signal from the audio source. 2) Audio cable is failure. Check audio signal input of the I310 TPA6021A4 pin 4, 5, 7, 8. Failure Point 1) Printed wire broke between P309 and I310 pin 4, 5, 7, 8.
  • Page 24 Continue Check I310 pin 14 SHOUTDOWNn if is low level. Failure Point 1) Printed wire broke between I306 pin 51 and Q309 and I310 pin 14. 2) R392, R390, R391 is open or short. 3) C400 is short. 4) Q309 is filure. 5) I306 is failure.

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W1907

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