Service Manual ViewSonic VA902/b Model No. VS10780 19” Color TFT LCD Display (VA902/b_SM Rev. 1a Oct.
Copyright Copyright ¤ 2005 by ViewSonic Corporation. All rights reserved. No part of this publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language or computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical, manual or otherwise, without the prior written permission of ViewSonic Corporation.
TABLE OF CONTENTS 1. Precautions and Safety Notices 1 2. Service Tools & Equipment Required 3 3. Circuit Theory 4 4. Disassembly & Assembly 15 5. Test and Adjustment 19 6. Troubleshooting 24 7. Recommended Parts List 32 8. Schematic Diagrams 42 9.
1. Precautions and Safety Notices 1. Appropriate Operation (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) Turn off the product before cleaning. Use only a dry soft cloth when cleaning the LCD panel surface. Use a soft cloth soaked with mild detergent to clean the display housing. Use only a high quality, safety approved AC/DC power cord. Disconnect the power plug from the AC outlet if the product will not be used for a long period of time.
(11) After installation of the TFT Module into an enclosure (LCD monitor housing, for example), do not twist or bend the TFT Module even momentarily. When designing the enclosure, it should be taken into consideration that no bending/twisting forces may be applied to the TFT Module from outside. Otherwise the TFT Module may be damaged. (12) The cold cathode fluorescent lamp in the LCD contains a small amount of mercury. Please follow local ordinances or regulations for disposal.
2. SERVICE TOOLS & EQUIPMENT REQUIRED 1. SIGNAL GENERATOR 2. MULTIMETER 3. SCREW DRIVER 4. OSCILLOSCOPE 5. Soldering IRON 6. SOLDER 7. VGA Cable (Black, 15pins point to point) 8. Color Analyzer 9. ISP Board 10. EDID Board 11. FOXISP. EXE file 12. EDID program file 13.
3. CIRCUIT THEORY 1. Block Diagram Block Diagram TFT LCD Panel 19" 12V Lamp2 Panel Interface 2 Rectifier & Filter Circuit 5V Power Lamp1 1 5V AP2301 PMBT3906 LDO 5V-3.3V 5V-1.8V 24C16 Power Transformer Feedback OVP Transformer1 Panel Enable On/Off Brightness On/Off AOP605L MCU W78E65p Rectifier & Filter Circuit OZ9910 Scaler TSU16AK Brightness XTAL2 14.318MHz LTV817 AOP605L XTAL1 22.
2. Electronic Circuit Theory 2.1 Switching Mode Power Supply 2.1.1 AC Current Input Circuit P801 is a connector for connecting AC Power. F801 is a fuse to protect all the circuit. AC input voltage is from 100V to 240V. R820 and R821 joined between two inputting main circuit to prevent man from shock. L801 is used to clear up low frequency wave. C801 and C806 are used to discharge the waves that L801 produced. High frequency waves are damped by C801 and C806.
dimming frequency is determined by R527 and C506. C502 is used for soft start and compensation, C502, C528 are used to filter noise. The output drives, including NDR4, NDRV2, PDRV3, PDRV1 (pins1, 3, 15, 16 respectively), generate a square pulses to drive MOSFET U501, U502. And U501, U502 works as full-bridge topology, it is high efficient, zero voltage switch. During start up, VSEN (pin9) detects the voltage at the transformer secondary. When VSEN reaches 3.0V, the output voltage is regulated.
Button “Key-2” is defined as two functions of selecting and adjustment, which is connected to U105 #25 through CN106 #1. Button “Key-Up” is defined as plus, which is connected to U105 #26 through CN106 #3. Button “Key-Down” is defined as minus, which is connected to U105 #27 through CN106 #5. Button “Key-1” is defined as two functions of menu and exit, which is connected to U105 #28 through CN106 #2. LED indicator on the front bezel is defined as follows: a.
T1 (ms) 0.1~10 T2 (ms) 0~10 T3 (ms) >200 T4 (ms) >100 T5 (ms) 0~50 T6 (ms) 0.1~10 T7 (ms) >1000 3 5. AC Outlet Pin Assignment 2 1 Pin Symbol Description 1 L Live 2 N Neutral 3 E GND P801 6. Inner Connector Pin Assignment 6.1 CN501, CN502, CN503, CN504 (Connect to Panel Backlight, SM02B-BHSS-1-TB or equivalent) Pin Symbol Description 1 2 H.V. L.V. High voltage for lamp Low voltage for lamp 6.2 CN101 (Power BD to Interface BD) Pin No.
6.4 CN103 (Connect I/F BD to panel, FI-X30S-H or Equivalent) Pin No.
7. Key Parts Pin Assignment 7.1 IC802 (TOP246Y, Power Control IC) Pin Symbol I/O 1 2 3 4 5 6 C L X S F D I I I O I I Description Control Line Sense External Current Limit Source of MOSFET(GND) Frequency Drain of MOSFET 7.2 IC501 (OZ9910G, CCFL inverter controller IC) Pin No.
Pin Symbol I/O Description 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 GND VDDP NC NC NC NC NC NC NC NC AD0 AD3 HWRESET XIN XOUT AVDD_MPLL GND HSYNC0 VSYNC0 GND NC NC GND NC NC VDD_ADC NC NC GND NC NC VDD_ADC REXT AVDD PLL GND AVDD ADC GND BINOM BINO GINOM Ground Digital Output Power Not connected Not connected Not connected Not connected Not connected Not connected Not connected Not connected DDR direct bus AD0; 4mA driving s
Pin Symbol I/O Description 74 75 76 77 PWM1 NC NC AD1 O I/O PWM1; 4mA driving strength Not connected Not connected DDR direct bus AD1; 8mA driving strength 78 AD2 I/O DDR direct bus AD2; 8mA driving strength 79 NC Not connected 80 NC Not connected 81 NC Not connected 82 NC Not connected 83 NC 84 VDDP Not connected Digital Output Power 85 GND Ground 86 GND 87 VDDC Ground Digital Core Power 88 NC Not connected 89 NC Not connected 90 NC Not connected 91 92 93 94 9
Pin Symbol I/O Description 119 LVB3M O 120 LVBCKP O B-Link Negative LVDS Differential Data Output B-Link Positive LVDS Differential Clock Output 121 LVBCKM O B-Link Negative LVDS Differential Clock Output 122 LVB2P O B-Link Positive LVDS Differential Data Output 123 LVB2M O B-Link Negative LVDS Differential Data Output 124 LVB1P O B-Link Positive LVDS Differential Data Output 125 LVB1M O B-Link Negative LVDS Differential Data Output 126 VDDP O Digital Output Power 127 GND
7.4 U105 (Micro-controller: W78E65P-40) Pin Symbol I/O 1 P4.2/INT3 2 P1,0/T2 O 3 P1.1/T2EX O 4 P1.2 I 5 P1.3/PWM0 O 6 P1.4/PWM1 O 7 P1.5/PWM2 O 8 P1.6/PWM3 9 P1.7/PWM4 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 RST P3.0/RXD P4.3/INT2 P3.1/TXD P3.2/INT0 P3.3/INT1 P3.4/T0 P3.5/T1 P3.6/WR P3.7/RD XTAL2 XTAL1 GND P4.0 P2.0/A8 P2.1/A9 P2.2/A10 P2.3/A11 P2.4/A12 P2.5/A13 P2.6/A14 P2.7/A15 PSEN ALE P4.1 EA P0.7/AD7 P0.6/AD6 P0.5/AD5 P0.4/AD4 P0.
4. Disassembly & Assembly 1.
EXPLODED PARTS LIST (VA902/b-1) ViewSonic Model Number: VS10780-1W Rev: 1a Serial No.
2.
3. Assembly Block CHASSIS*1 FRONT BEZEL (G/S)*1 LED LENS*1 LOGO PLATE,THREE BRID*1 BUTTON FUNCTION KEY*1 INSULATOR,MYLAR*1 IF BOARD*1 POWER BOARD*1 FFC CABLE*1 CLIP,WIRE*1 (SCREW,PW,CROSS,M3*5, Ni*5) (BOLT, #4-40x11.
5. TEST AND ADJUSTMENT 1. Key Function Description CONTROL KEY KEYS FUNCTION [AUTO] [2] By pressing [AUTO] key, “Auto Image Adjust” is performed [MENU] [1] By pressing [MENU] key, Main menu display [▼] [▲] A. When “MENU OSD” display, press these keys to change the contents of an adjustment item, or change an adjustment value B. When “MENU OSD” is un-display, press these keys to change brightness and contrast [POWER] Power on or power off the monitor 2.
3. OSD Control 3.
3.
6. EDID (Rewrite EDID data to EEPROM) If we need to rewrite the EEPROM data, please confirm the following steps. 1. Plug in VGA Cable; we can rewrite the EDID data to EEPROM by using “EDID Rewrite” program. 2. If the “EDID Rewrite” process finished, please pull out VGA cable and press ‘’2’’+’’▲’’ at the same time. 3. Pull out AC power cable or press power key to restart. 7. Upload firmware to MCU via VGA Cable 7.
8 After repair, to ensure the quality you should do the following test and adjustment Item Content Equipment Test OSD function 1.Signal is set as 1280x1024@60Hz 2. LCM button are from left to right, checking whether each single function key and compound function key can be worked. Chroma Signal Generator Contrast Check 1. Set input mode to 1280x1024@60Hz 2. Set Pattern to 32 gray shades 3. Set contrast to the max. The brightest 5~6 shades brightness cannot be distinguished.
6. TROUBLE SHOOTING 1. z z z z z z z z Common Acknowledge If you change the interface board, be sure that the U105, U106 and U103 these three components also changed to the new I/F board because there was program inside. If not, please re-write EDID or upload firmware into MCU via VGA Cable. If you adjust clock and phase, please do it at the condition of Windows shut down pattern. If you confirm the R.G.B. color is normal or not, please do it under 16-grey scalar pattern. This LCM is analog interface.
2. No Power & Power LED Off No power Check circuit if short Check primary rectifier voltage Check IC802, C805, T801 Check F801, P801, D801 Check pin3 of IC802 voltage about 1V Check R801, R805, R822, R823, R817 Check R803, R807, R824, R825 Check pin2 of IC802 voltage about 2V Check R812, R816, C818 Check pin1 of IC802 voltage is 5.
3. DC output voltage is unstable Output Voltage Unstable Check Vbe of Q801 below 0.
4. Output power is unstable Unstable power Check sampling Circuit Check R810, R811, R818 Change R810, R811, R818 Check the C pin voltage of IC803 if 3V Check the R pin voltage of IC803 about 2.5V Change IC803 Check R809, R808, R814, D809 Check pin1 of IC802 voltage is 5.
5. Backlight can’t be turned on No raster? Yes LED Green? Yes Backlight cannot be turned on.
6.
7.
8. Bad Screen Bad Screen OK LVDS Cable Reinsert Workmanship NG OK Change LVDS Cable LVDS Cable NG NG NG Check Crystal:pin20,21 of U105 and pin 33,34 of U104 1.Check X101,C154,C155 2.
7. RECOMMENDED PART LIST RECOMMENDED SPARE PARTS LIST (VA902-1) ViewSonic Model Number: VS10780-1W Rev: 1a Serial No.
RECOMMENDED SPARE PARTS LIST (VA902b-1) ViewSonic Model Number: VS10780-1W Rev: 1a Serial No.
BOM LIST (VA902-1 for "Hannstar (8ms) Panel") ViewSonic Model Number: VS10780-1W Rev: 1a Serial No. Prefix: PSS Item 1 2 3 4 5 6 7 8 9 ViewSonic P/N #N/A #N/A #N/A #N/A #N/A #N/A P-00003670 P-00003669 P-00003668 Ref.
Item ViewSonic P/N Ref.
BOM LIST (VA902b-1 for "Hannstar (8ms) Panel") ViewSonic Model Number: VS10780-1W Rev: 1a Serial No. Prefix: PSW Item 1 2 3 4 5 6 7 8 9 ViewSonic P/N #N/A #N/A #N/A #N/A #N/A #N/A P-00003670 P-00003669 P-00003668 Ref.
Item ViewSonic P/N Ref. P/N 61 62 #N/A #N/A 506380002100 506431002050 Description TAPE,WRAPPING TYPE(VIEWSONIC),50mmx75M,LE1709 FILM,PROTECTION,UNPRINTED,LE1909/18 Location Qty. For VSA For VSA 0.0083 ROL 0.
8. SCHEMATIC DIAGRAM Power Supply C820 2200P Y 1 C805 C807 100u 450V 33n 400V/ NC ZD802 P6KE200A +14V C808 1000u 25V C811 1n 500V 1 C810 220u 25V 4 R828 100R 1W ZD801 9.1V 2 R829 200R 3 R827 10K C822 0.1u 50V ZD803 5.6V ZD804 16V C815 47u/25V R812 6R8 L F R816 6R8 C818 47u/25V C817 0.
Inverter +14V H C522 220uF/25V C511 2.2uF/25V R501 3M/3kv + T501 EEL-19 22:2600 C537 NC D513 SKS20-04AT 2 1 J507 33R 1/4W R528 124K 1% R522 88.7K 1% NDRV2 4 5 C529 220P G/ 50V R523 62K 1% 6 7 BRIGHTNESS 8 C504 1n/50V R524 360K 1% 15 PDRV1 NDRV1 HSB GNDA VIN CT V5000 LCT ISEN DIM CMP_SST ENA VSEN 1 2 3 4 16 PDRV2 PGND 3 J501 33R 1/4W 14 C528 1.0u/25V 13 12 10 C503 100n/50V 9 1 2 3 4 C502 2.2u/25v R509 1.5K 1.5K 1.5K 1.5K R511 Q504 Q505 1.
DC Input U102 FS8860-33PJ VCC5V VCC3.3 2 C102 0.1/50V VCC3.3 VAA1 ADJ VOUT + C103 100uF/16V 1 + VIN C104 0.1/50V VAA1 VAA2 VAA2 VAA3 VAA3 VAA4 CN101 4500-06 U101 FS8860-18PJ VOUT VIN 2 + C101 100uF/16V C111 0.1/50V VCC1.8 + C107 0.1/50V C106 100uF/16V 1 + BRIGHTNESS ON/OFF VCC1.8 ADJ 3 VCC5V 1 2 3 4 5 6 VAA4 R174 9.
VGA Input 16 PC5V_VGA 11 1 6 2 7 3 8 4 9 5 10 12 13 14 R166 0 VGA_G R167 0 VGA_B R168 0 R111 75 1% R112 75 1% R113 75 1% R115 R121 R116 R122 R117 R123 R118/NC 22 47 22 47 22 47 470 C115 C121 C116 C122 C117 C123 NC/C118 47n/25V 47n/25V 47n/25V 47n/25V 47n/25V 47n/25V 1000P/50V R114 10K R107 100 RIN GNDR GIN GNDG BIN GNDB SOG VCC5V TVS101 BAV99 17 15 VGA_R CN102 DZ11AA1-HW6 TVS102 BAV99 C165 NC C166 NC C167 NC TVS103 BAV99 HPD_VGA VCC5V DET_VGA DDC_SCL_VGA DDC_SDA_VGA DD
Scaler VAD VPLL VDVI VDPLL VPO VCC3.
Panel Interface CN103 AL2309-A0G1Z PB[0..9] PA[0..9] PB9 PB8 PB7 PB6 PB5 PB4 RXO0RXO0+ RXO1RXO1+ RXO2RXO2+ PB3 PB2 PB1 PB0 PA9 PA8 RXOCRXOC+ RXO3RXO3+ RXE0RXE0+ PA7 PA6 RXE1RXE1+ PA5 PA4 PA3 PA2 PA1 PA0 RXE2RXE2+ RXECRXEC+ RXE3RXE3+ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 VLCD VLCD CN104 DUPON2.
MUC RP101 10K 100 100 16 17 18 VCPU 1 2 3 4 8 9 23 33 34 RP104 10K 2 3 4 5 6 7 8 7 6 5 PANEL_ENABLE CCFL_ENABLE DET_VGA VCPU Q104 PMBT3906 LED_GREEN R158 51 R143 4K7 R144 4K7 P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 C154 12p/50V 4 3 2 1 4 3 2 1 5 6 7 8 10K 5 6 7 8 5 6 7 8 4 3 2 1 R134 44 P3.3/INT1 P4.2 VCPU R145 220 P3.7 20 R142 220 P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P1.6/PWM3 P1.7/PWM4 P4.0 ALE P4.1 X2 1 C153 NC/10u/16V P4.3/INT2 P3.4/T0 P3.5/T1 P3.6/WR P3.1/TXD P3.
Key Pad LED101 GREEN LED_GREEN LED_ORANGE KEY_MENU/EXIT KEY_SELECT/AUTO KEY_POWER KEY_DOWN KEY_UP ORANGE SW101 SW102 SW103 SW104 6 8 2 1 4 5 3 7 SW105 CN106 2x4PIN SW TACT SW TACT SW TACT MENU/1 AUTO/2 POWER SW TACT DOWN SW TACT UP ViewSonic InnoLux LE1909(VA902/b) Document Number : 0921341039 SIZE : A4 APPRO BY : TITLE : CHECK BY : KEYPAD 2005-06-02 DATE : SHEET Confidential - Do Not Copy ViewSonic Corporation 45 VA902/b 2 OF VA902/b 2 DRAWN BY : Rev : V01
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POWER board Confidential - Do Not Copy ViewSonic Corporation 47 VA902/b
*Readers Response* Dear Readers: Thank you in advance for your feedback on our Service Manual, which allows continuous improvement of our products. We would appreciate your completion of the Assessment Matrix below, for return to ViewSonic Corporation. Assessment A. What do you think about the content of this Service Manual? U nit Ex cellent Fair G ood Bad 1. Precautions and Safety Notices 2. Specification 3. Front Panel Function Control Description 4. Circuit Description 5.
