ViewSonic VA712-2 Service Manual Download Page 17 | Manualshive

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ViewSonic VA712-2 Service Manual Download Page 17

ViewSonic Corporation

Confidential - Do Not Copy

VA712-2_ VA712b-2

14

4. Circuit Description

4.1 LCD MONITOR DESCRIPTION

The LCD MONITOR will contain a Main Board, an Power Board, 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.

Power Board

(Include: adapter, inverter)

Flat Panel and

CCFL backlight

Main Board

Key Board

RS232 Connector
For white balance
adjustment in factory
mode

HOST Computer

CCFL Drive.

AC-IN

100V-240V

Video signal, DDC

Monitor Block Diagram

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Summary of Contents for VA712-2

Page 1: ...ViewSonic VA712 2 VA712b 2 Model No VS10901 17 Color TFT LCD Display VA712 2_ VA712b 2_SM Rev 1a Apr 2006 ViewSonic 381 Brea Canyon Road Walnut California 91789 USA 800 888 8583 Service Manual...

Page 2: ...er expressed or implied with respect to the contents hereof and specifically disclaims any warranty of merchantability or fitness for any particular purpose Further ViewSonic reserves the right to rev...

Page 3: ...ty Notices 1 2 Specification 4 3 Front Panel Function Control Description 8 4 Circuit Description 14 5 Adjustment Procedure 26 6 Troubleshooting Flow Chart 49 7 Recommended Spare Parts List 50 8 Explo...

Page 4: ...et unplug the power cable immediately and consult your service technician Always unplug the monitor before cleaning it Clean the cabinet with a clean dry cloth Apply non ammonia based cleaner onto the...

Page 5: ...he front cover of the monitor Do not touch the surface of the polarizer Surface of the LCD panel is pressed by fingers and that may cause Mura Take out the monitor with cushions Taking out the monitor...

Page 6: ...on foreign objects That could scratch the surface of the panel or cause Mura Place the monitor on the lap the panel surface must be upwards The panel is placed facedown on the lap That may cause Mura...

Page 7: ...Horizontal 140 Vertical 130 Contrast Ratio 500 1 Typ Brightness 300 cd Typ Response Time 8ms Typ Active Display Area 337 9mm H x 270 3mm V Maximum Pixel Clock 135 MHz Horizontal Frequency 30 82 kHz V...

Page 8: ...es Yes 8 800 x 600 56Hz 35 1kHz Yes Yes 9 800 x 600 60Hz 37 9kHz Yes Yes 10 800 x 600 72Hz 48 1kHz Yes Yes 11 800 x 600 75Hz 46 9kHz Yes Yes 12 800 x 600 85Hz 53 7kHz Yes Yes 13 832 x 624 75Hz 49 7kHz...

Page 9: ...NNECTOR 1 5 6 10 11 15 Pin Number Pin Function 1 Red video input 2 Green video input 3 Blue video input 4 No Connection 5 Ground 6 Red video ground 7 Green video ground 8 Blue video ground 9 5V 10 H V...

Page 10: ...n 9 RX1 TMDS negative differential input channel 1 10 RX1 TMDS positive differential input channel 1 11 GND Logic Ground 12 Reserved 12 Reserved No connection 13 Reserved 13 Reserved No connection 14...

Page 11: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 8 3 Front Panel Function Control Description...

Page 12: ...he control screen tells what to do next from this screen You can toggle between control screens adjust the selected option or exit the screen 4 To adjust the setting press the up or down T buttons 5 T...

Page 13: ...lor Adjust provides several color adjustment modes including preset color temperatures and a User Color mode which allows independent adjustment of red R green G and blue B The factory setting for thi...

Page 14: ...vertical frequency NOTE VESA 1280 x 1024 60Hz recommended means that the resolution is 1280 x 1024 and the refresh rate is 60 Hertz Manual Image Adjust Sub menu H Size Horizontal Size adjusts the wid...

Page 15: ...an 1280 x 1024 the following screen appears OSD Position allows the user to move the OSD menus and control screens OSD Timeout sets the length of time the OSD screen is displayed For example with a 30...

Page 16: ...0 or 640x400 mode 1 White Balance Not shown on user s guide 1 Power Lock Press and hold 2 for 10 seconds If the power button is pressed the message Power Button Locked will display for 5 seconds With...

Page 17: ...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 Power Board Include ad...

Page 18: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 15 4 2 POWER BLOCK FUNCTION DESCRIPTION Inverter Block Function...

Page 19: ...user s settings and restore the factory defaults Auto Image Adjust Please select and enter Auto Image Adjust function on Main Menu to see if it is workable The Auto Image Adjust function is aimed to...

Page 20: ...n frame White Balance Test Signal 640 480 60Hz Test Pattern White and Black Pattern 1 5 8 R G B Colors Contrast Test Signal 1280 1024 60Hz Test Pattern R G B Color Intensities Pattern and 16 Gray Scal...

Page 21: ...720 60Hz 1280 1024 60Hz Normally when the primary mode 1280 1024 60Hz is well adjusted and compliant with the specification the secondary display modes will also be compliant with the spec But we sti...

Page 22: ...ch out Max current driving 1A 58 BJT_B Embedded regulator P type BJT control pin out 5 TMDS_TST TMDS_TEST Pin Power on latch for host interface type 7 13 TMDS_VDD TMDS power 3 3V 6 REXT Impedance Matc...

Page 23: ...or flat panel display applications It includes an 8051 CPU core 768 byte SRAM 4 channels of 6 bit ADC 3 external counters timers 6 channels of PWM DAC VESA DDC interface and a 64K byte internal progra...

Page 24: ...output General purpose I O open drain DA5 P5 5 7 1 PWM DAC output General purpose I O open drain P5 6 HSCL2 8 2 General purpose I O Slave llC1 SCL2 open drain P5 7 HSDA2 9 3 General purpose Output Sla...

Page 25: ...ose I O COMS P6 6 CLKO1 30 24 General purpose I OCLKO1 COMS P6 7 31 25 General purpose I O COMS VSYNC 32 26 VSYNC input P1 7 36 30 General purpose I O Standard 8051 CMOS P1 6 37 31 General purpose I O...

Page 26: ...me Function 1 GND Ground 2 COMP Voltage feedback pin same as the COMP pin in UC384X By connecting a photo coupler to close the control loop and achieve the regulation 3 VCC Supply voltage pin 4 RT Thi...

Page 27: ...ristics NO Name Function Description NO Name Function Description 1 GNDT Ground 8 FB Feedback Input 2 Vds Dimming Voltage Input 9 COMP Error Amplifier Output 3 Vref Reference Voltage 10 S S Soft Start...

Page 28: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 25...

Page 29: ...allowed for warm up before proceeding White Balance adjustment 1 Adjust of White Balance 1 How to do the Chroma 7120 MEM Channel setting A Reference to Chroma 7120 user guide B Use SC key and NEXT ke...

Page 30: ...e LCD indicator on Chroma 7120 will show x 0 283 0 02 y 0 298 0 02 Y 250 cd m2 4 Adjust the RED of color1 on factory window until chroma 7120 indicator reached the value R 100 5 Adjust the GREEN of co...

Page 31: ...value B 100 7 Repeat above procedure item 4 5 6 until Chroma 7120 RGB value meet the tolerance 100 5 D Adjust 5000 color temperature 1 Switch the chroma 7120 to RGB Mode with press MODE button 2 Swit...

Page 32: ...sh auto alignment and save press before change to next mode 3 Until all of modes are adjusted exit OSD menu and press POWER OFF to exit factory mode 5 4 Factory Defaults Item Defaults Item Defaults Co...

Page 33: ...4 x 768 70Hz 56 5kHz 1024 x 768 72Hz 58 1kHz 1024 x 768 75Hz 60 0kHz 1280 x 1024 60Hz 63 4kHz 1280 x 1024 75Hz 79 97kHz 1280x 720 60Hz 45kHz Function Test Display Pattern Item Test Content Pattern Spe...

Page 34: ...Figure1 Gray Scale Pattern Figure2 Horizontal Vertical Thickness Pattern R Color Pattern Figure 4 Figure 3 G Color Pattern Figure 5 B Color Pattern Figure 6 ViewSonic Corporation Confidential Do Not C...

Page 35: ...Full White Pattern Figure 7 Dark Screen Pattern Figure 8 Black White Pattern Figure 9 ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 32...

Page 36: ...e connected to GND PC Personal Computer LPT Cable P N 42 59906 001 1 Firmware Upgrade Program One additional monitor for checking the program execution 2 Setup Procedure 2 1 Connect P1 of Fixture with...

Page 37: ...rmware Upgrade Procedure Step 1 Let VA712 2 VA712b 2 set to be connected with AC cable and VGA cable Step 2 Execute the MSstar ISP tool ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2...

Page 38: ...on Open a new window to key in security code Step 4 Set Command NO to 4 and key in security code 94 94 ac ca 53 to shown as following then press OK button to close window ViewSonic Corporation Confide...

Page 39: ...the MTV512M64 viewed on your set Step 6 Click Load MCU File button Select the object bincode on your corresponding directory Step 7 Click button to finish the selection of bincode ViewSonic Corporati...

Page 40: ...g action by clicking the RUN button Step 9 If the flashing F W has been completed the message of Check MCU CRC OK on the right TextBox means the Host verify ok for the progress of program ViewSonic Co...

Page 41: ...712 2 VA712b 2 by VGA Cable 3 2 2 Connect P3 of Fixture with DVI port of VA712b 2 by DVI DVI Cable 3 2 3 Connect P1 of Fixture with Printer port of PC by LPT Cable 3 2 4 Plug Power Adapter to Fixture...

Page 42: ...3 3 DDC Key In Procedure Sep1 Select and execute DDC Key In program ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 39...

Page 43: ...Sep2 Inpute the S N and execute Enter ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 40...

Page 44: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 41...

Page 45: ...Sep3 Key the Enter and write the data ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 42...

Page 46: ...Sep4 If ddc program OK and show data compare ok ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 43...

Page 47: ...showed in the following picture 11 6 Disassemble the 4 fixed screws in the shield remove the shield as the direction arrowhead showed refer to the following picture 12 7 Disassemble the 4 screws and 4...

Page 48: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 45 1 1 3 Show pictures Picture 1 Picture 2 Picture 3 Picture 4 Picture 5 Picture 6...

Page 49: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 46 Picture 7 Picture 8 Picture 9 Picture 10 Picture 11 Picture 12...

Page 50: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 47 Picture 13 Picture 14 Picture 15...

Page 51: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 48 Picture 16 Picture 17 Picture 18 Picture 19 Picture 20...

Page 52: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 49 6 Troubleshooting Flow Chart...

Page 53: ...26 IC M24C16 WMN6TP E 00004982 56G1133 56 U404 1PCS 27 LCD PANEL E 00005619 750GLC70A7Q 12 1PCS 28 SPEAKER E 00005620 78G 311 8 L 1PCS 29 SPEAKER E 00005621 78G 311 8 R 1PCS 30 IC AMPLIFIER E TDA749 E...

Page 54: ...EAKER E 00005621 78G 311 8 R 1PCS 29 AIC1084 33PM TO 263 E 00005651 56G 563 7 U701 1PCS 30 PANEL E 00005657 750GLC70A7Q 12 B 1PCS 31 RTD2523B LF PQFP 128 E 00005658 56G 562116 U401 1PCS 32 MTV512MV PL...

Page 55: ...CKER 1 31 DC 00005635 40G581B709 4A S N LABEL 1 32 DC 00005617 41G7801709 6A QSG 1 33 N A 44G3231502 ELECTRIC COTTON 2 34 P 00005640 44G3783 1 EPS R 1 35 P 00005641 44G3783 2 EPS R 1 36 P 00005642 45G...

Page 56: ...2120 SCREW 4 71 HW 00005630 Q1G 130 6120 SCREW 2 72 N A Q1G 330 8128 SCREW 3 73 N A Q1G 330 8128 SCREW 2 74 N A Q1G 330 10 47 SCREW 1 75 HW 00005633 Q1G1030 8128 SCREW 4 76 HW 00005634 Q1G1040 10128 S...

Page 57: ...38 40G581B709 2B BLUE STICKER 2 1 31 DC 00005639 40G581B709 3A 8ms STICKER 1 32 DC 00005635 40G581B709 4A S N LABEL 1 33 DC 00005617 41G7801709 6A QSG 1 34 N A 44G3231502 ELECTRIC COTTON 2 35 P 000056...

Page 58: ...W 3 70 HW 00005628 M1G1730 6128 SCREW 2 71 HW 00005629 M1G1740 12120 SCREW 4 72 HW 00005630 Q1G 130 6120 SCREW 2 73 HW 00005660 Q1G 330 8128 SCREW 2 74 HW 00005660 Q1G 330 8128 SCREW 3 75 N A Q1G 330...

Page 59: ...8 Exploded Diagram and Exploded Parts List ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 56...

Page 60: ...22 HW 00005628 M1G1730 6128 SCREW 8 23 N A 52G 1207 A AL FOIL 1 24 N A 52G 1217 VS AL FOIL 2 25 N A 52G 1901 A AL FOIL 2 26 HW 00005629 M1G1740 12120 SCREW 4 27 HW 00005630 Q1G 130 6120 SCREW 2 28 N...

Page 61: ...EW 1 22 HW 00005628 M1G1730 6128 SCREW 8 23 N A 52G 1207 A AL FOIL 1 24 N A 52G 1217 VS AL FOIL 2 25 N A 52G 1901 A AL FOIL 2 26 HW 00005629 M1G1740 12120 SCREW 4 27 HW 00005630 Q1G 130 6120 SCREW 2 2...

Page 62: ...GNAL CABLE 1 14 N A 37G1754 4Z B BASE 1 PACKING PART LIST VA712 2 ViewSonic Model Number VS10901 3W Rev 1A Item ViewSonic P N Ref P N Location Q ty 1 P 00005662 J44G3783709 1C CARTON 1 2 N A 50G 600 2...

Page 63: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 60 9 Block Diagram...

Page 64: ...ete R715 R720 C712 VCC 5V BL_ON_OFF VIN 3 GND 1 VOUT 2 U702 NC AP1117 1 8V OUT_R OUT_L OUT_L OUT_R R722 4 7K 1 16W R706 10K 1 16W R707 10K 1 16W Q704 PMBS3904 DEL R702 R703 STDBY MUTE R723 10K 1 16W 5...

Page 65: ...OUT_R IICSDA IICSCL R4003 100 1 16W R4002 100 1 16W NC 1 NC 2 NC 3 VSS 4 SDA 5 SCL 6 WC 7 VCC 8 U404 M24C16 MCU_VCC MCU_VCC R4008 4 7K 1 16W EEPROM_WP C448 0 1uF R478 4 7K 1 16W R442 100 1 16W C E B...

Page 66: ...401 Q402 PMBS3906 C406 22uF 16V RXO3 RXO3 RXOC RXOC RXO1 RXO2 RXO2 RXO1 RXEC RXE3 RXE3 RXO0 1 8DVCC R1 8AVCC RXE2 RXE1 RXE0 RXE1 RXE0 RXEC RXE2 DGND DGND MCU_RST C414 0 1uF 33VRST_REF C418 10uF 16V R1...

Page 67: ...24 0 047uF D421 UDZS5 6B DDC2_SCL DGND DDC_SDA DGND DDC_SCL DGND DDC2_SDA DGND D416 UDZS5 6B DDC2_SDA DDC2_SCL B1 VGA_B D418 UDZS5 6B HSIN D420 UDZS5 6B D422 UDZS5 6B R4012 0 1 16W DATA2 1 DATA2 2 DAT...

Page 68: ...206 0 1uF 25V D201 RB050L 40 R217 1KO 1 10W TP4 HVL 1 D209 MLL4148 C210 10pF 3KV ON OFF C211 0 33uF 250V R213 1 5KO 1 10W R207 68KO 1 10W R223 1KO 1 10W R209 47KO 1 10W Q204 PMBS3904 R205 1 8KO 1 4W R...

Page 69: ...50V DB901 KBP206G 1 4 3 2 C923 1000uF 16V IC903 KIA431A AT P R925 1KO 1 10W 5V 12V R929 2 4KO 1 10W 1 R915 10KO 1 10W R921 47O 1 2W SW901 SW R928 3 9KO 1 10W R926 33KO 1 10W 1 R903 430KO 1 8W R917 10...

Page 70: ...VAROUT_R 7 NC 8 INR 9 SVR 10 STBY 11 MUTE 12 GND 13 OUTR 14 VS 15 VS 16 OUTL 17 GND 18 GND 19 GND 20 U201 TDA7496L C203 0 1uF C212 100pF R207 1K R210 20K 1 16W R208 1K C206 0 47uF 25V R201 18K 1 16W...

Page 71: ...SW001 SW KEY 1 KEY DOWN LCD ON OFF GND LCD ON OFF KEY 2 KEY 1 KEY DOWN KEY UP GND MUTE 2 4 6 8 10 12 1 3 5 7 9 11 CN006 CONN LED ORANGE LED GREEN SW003 SW SW004 SW SW005 SW SW006 SW GND SPKR_R SPKR_L...

Page 72: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 69 11 PCB Layout Diagrams 11 1 MAIN BOARD PCB TOP VIEW...

Page 73: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 70 11 2 MAIN BOARD PCB BUTTON VIEW 11 3 KEYBOARD TOP VIEW 11 4 KEYBOARD BUTTON VIEW...

Page 74: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 71 11 5 POWER PCB TOP VIEW...

Page 75: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 72 11 6 POWER PCB BUTTON VIEW...

Page 76: ...ViewSonic Corporation Confidential Do Not Copy VA712 2_ VA712b 2 73 11 7 AUDIO PCB TOP VIEW BUTTON VIEW...

Page 77: ...Circuit Description 5 Adjustment Procedure 6 Troubleshooting Flow Chart 7 Recommended Spare Parts List 8 Exploded Diagram and Exploded Parts List 9 Block Diagrams 10 Schematic Diagrams 11 PCB Layout...

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