ViewSonic N4251w-1M Service Manual

Service Manual ViewSonic N4251w-1MModel No. VS11502-1M 42” LCD TV (N4251w-1M_SM Rev. 1b Jul. 2007)ViewSonic® 381 Bre

7. Mechanical The following table defines the mechanical specifications of this product for both chassis and cabinet. Parameter Specifica

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription254 N/A 2347647596P CAP,CHIP 85'CCS 0805/Y5V/16V 4.7u Z T C266 1

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription340 N/A 2346110496P CAP,CHIP 125'CCS 0603/X7R/50V 0.1u K T C378

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription426 N/A 2346110496P CAP,CHIP 125'CCS 0603/X7R/50V 0.1u K T C522

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription512 N/A 2346110396P CAP,CHIP 125'CCS 0603/X7R/50V 0.01u K T C610

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription598 N/A 2346110496P CAP,CHIP 125'CCS 0603/X7R/50V 0.1u K T C734

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription684 N/A 2336347611P CAP,MINI ELE 105'CEC 47u/ 16V 5*7 P=2.0 C C

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription770 E-IC-0401-2745 2365810796P IC,LINEAR(SMD)AP1084K33LA TO-263 ATC

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription856 N/A 2379360006P BEAD,HI-IMPEDANCEZ= 60 ohm(200MHZ~) 0603 300mAL120 185

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription942 N/A 2407430900P SOCKETDHSB-15FTF7 BLUE(661C) LEOCOP106 1943 N/A 24051

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription1028 E-Q-0402-1624 2360301696P XISTOR,NPN R SMD PMBS3904 SOT-23 PHIL

3. Front Panel Function Control DescriptionFront View of the ProductENGLISH Note:1. Press VOL+ and MENU buttons at the same time to lock power button,

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription1114 E-R-0405-6419 2253247296P RES CHIP 1/10W RC 0603 1/10W 4.7Kohm J

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription1200 N/A 2253233296P RES CHIP 1/10W RC 0603 1/10W 3.3Kohm J T R344 112

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription1286 N/A 2253210396P RES CHIP 1/10W RC 0603 1/10W 10Kohm J T R468 112

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription1372 N/A 2251213016P RES,CHIP 1/10 RC 0603 1/10W 1.3Kohm F T R850 1137

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription1458 M-SW-0815-0182 2403702200P TACT SWITCHTSAA-2 HUAJIE S

* Reader’s Response* Dear Readers: Thank you in advance for your feedback on our Service Manual, which allows continuous improvement of our products.

Rear View of the ProductENGLISH Power (AC input)Using power cord provided, connect to a power source.Air TV inputConnect to NTSC or ATSC TV source.Cab

Remote ControlViewSonic Corporation Confidential - Do Not Copy N4251w-1M 10

ENGLISHA SOURCES Select input sourceBPIP * PIP: activate PIP featurePIP Source: change PIP sourcePIP Size: change PIP sizeC0~9, -/100 number button In

ENGLISHVideo Menu — To adjust the picture qualityVideo Menu is active in all except the VGA input source. • Contrast: To adjust contrast of video. (ri

ENGLISHSetup Menu — To set up OSD windowSetup Menu is active in all input sources. (However, when in VGA input source, there is no “V-Chip” function i

ENGLISHThe movie Ratings in the US are defined as following.Use ENTER button to block or unblock the ratings, and use MENU to exit.G General audience R

ENGLISHThe TV Ratings in the US are defined as following.Use ENTER button to block or unblock the ratings, and use MENU to exit.TV-Y All children TV-PG

ENGLISH • Tuner Mode: To select Cable or Air as the TV source. Select “Cable” if you want to watchCable TV channels, and select “Air” to watch Air TV

Copyright Copyright © 2007 by ViewSonic Corporation. All rights reserved. No part of this publication may be reproduced, transmitted, transcribed, s

ENGLISHVGA Menu — To set up for computerIt is only active in VGA source. • Auto Adjust: Press ENTER to auto adjust picture’s horizontal position, vert

ENGLISHADVANCED OPERATION — REMOTE CONTROLPIP/POPPIP/POP button allows you to watch two screens from different sources at the same time. (PIP is pictu

4. Circuit Description A. Analog Switch and Video input. MT8202 is a highly integrated video and audio single chip processor for emerging HDTV-Ready

C. DTV and HDMI. MT5112 is a fully integrated single-chip 8-VSB and 64/256-QAM demodulator. The chip is designed specifically for the digital terre

165 MHz and video resolutions up to 1080p and UXGA. The MT8293 supports the DVD-Audio standard, including 7.1- surround audio at 96kHz a

D. Audio MT8202 incorporates a on-chip audio processor decodes whole world standard audio signals from tuner with lip sync con

5. Adjusting Procedure 1. Function Test 1.1. Product - 42” LCD TV 1.2. Test Equipment -PC signal generator: CHROMA 2525 CARD ,CHROMA 2327 or 232

3.Under the picture NTSC color bar of YPbPr source, select WHITE BALANCE and press ENTER, The color warm will auto adjust. The act of EHITE BALANCEL i

SPEAKER output is right. Meets earphone with the EARPHONE, Determined whether the action of EARPHONE output is normal. 1.4.11 All Modes Reset After

U.S.A Channe2 (TABLE 2) VIF45.75 MHz, SIF 41.25 MHz (Unit：MHz) Ch. Freq.range fp (picture)

TABLE OF CONTENTS 1. Precautions and Safety Notices... 13. Front Panel Function Control

1.5. TV receiving test: 1.5.1 TV SIGNAL TEST ITEM CENTRALISM TRANSMITTING SIGNAL CHECK CONTENT SET CONTENT CHANNEL ORDER FREQUENCY (MHz) PATTERN SO

TIMING TABLE (FACTORY PRESET MODE) (TABLE 3) ITEM 1 2 3 4 TIMING 640 ×480 60HZ 640 ×480 75HZ 800 ×600 60HZ 800 ×600 75HZPixel Rate 25.1

TIMING TABLE (FACTORY PRESET MODE) (TABLE 3) ITEM 9 10 11 12 TIMING 1360 ×768 60HZ 1280 ×1024 60HZ Pixel Rate 85.5MHZ 108MHZ H TOTAL 2

2. VGA DDC Key In Procedure Note: 1. Every time after replacing the main board, you have to do the DDC key in. 2. If you find the DDC does not confo

2.2.2 Barcode Reader connects with keyboard and PC keyboard port. 2.2.3 Connect DDC Card and N4251W(1M) LCD TV with VGA Cable. (when key in DVI DDC

2.3.3 Press “ENTER” key. 2.3.4 Input bar code 2.3.5 Press “ENTER” key, then the successful picture is as follows. “DDC

3. HDMI DDC Key In Procedure There are three EDID files for the different HDMI connectors. So you must be download the different EDID into each HDM

3.2.2 Barcode Reader connects with keyboard and PC keyboard port. 3.2.3 Connect DDC Card and N4251W(1M) LCD TV with HDMI Cable. 3.2.4 Connect

3.3.3 Press “ENTER” key. 3.3.4 Input bar code 3.3.5 Press “ENTER” key, then the successful picture is as follows. “DDC DO

4. Firmware Upgrade Procedure When you receive the returned LCD TV, please check whether the firmware version is the latest. If not, please do the f

1. Appropriate Operation (1) Turn off the product before cleaning. (2) Use only a dry soft cloth when cleaning the LCD panel surface. (3) Use a s

4.5.2 Select COM port. Depends on the COM port assigned in System Device Manager (Refer below right). 4.5.3 Select Baud Rate. 115200x 8 (Sugge

4.5.4 Enable the USB Bridge. 4.5.5 Browsing the File to download. ViewSonic Corporation Confidential - Do

4.5.6 Press Upgrade to download file. Note : 1. The Baud Rate is auto setting if mismatch found between your platform and Mtktool. 2. You can sl

Packing For Shipping And Disassembly Procedure Packing For Shipping 1. Packing Procedure 1.1 Paste protection film to protect the LCD TV. (Figure 1

Item ViewSonic P/N Ref. P/N Description Q'ty1 N/A N4251W(1M) monitor 12 P-00008063 2013054045P POLYETHY BAG 13 P-00008104 2012196600P POLYFOAM (T

Disassembly Procedure 1. Disassembly of Stand and Dust Cover from LCD TV. 1.1 Unscrew 4 screws that secure Stand Unit and detach Dust Cover from t

2.3 Prize the rectangle hole on Rear Cover (Fig.1) with a screwdriver(Fig.2) to make the Rear Cover detach from the LCD TV.

3. Disassembly of Main Board,Power Board,IR Board,Speaker,Front Cover and Panel Unit. 3.1 Unscrew 24 screws to remove Shield Plate.

3.2. Unscrew 4 screws to remove speaker. Speaker ViewSonic Corporation Confident

3.3. Remove the function key ass’y. 3.4. Unscrew 18 screws to remove Front Cover and Bracket Fix. ViewSonic Cor

(14) The LCD module is designed so that the CFL in it is supplied by Limited Current Circuit (IEC60950 or UL1950). Do not connect the CFL in Hazardo

3.5. Unscrew 17 screws to remove metal fiting vesa support. Bracket,fixViewSonic Corporation

3.6. Unscrew 13 screws and disconnect the wires to remove Main Board. 3.7. Unscrew 4 screws and disconnect the wires to remov

3.8. Unscrew 5 screws to remove metal fiting-io. 3.9. Lay Panel Unit facedown and unscrew 18 screws on its right,left,up and down sides, to

Panel Unit ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 50

6. Trouble Shooting Flow Chart 6.1. NO VOICE TVCheck I134 Pin3,13has output signal?Replace I134AV,S-VIDEO,YPbPrNoCheck I106 has I2Ssignal outpu

6.2. NO POWER Chcek P8055V,12VCheck 3.3V is on C113?1.9V is on I102 Pin2?YesYesYesYesReplace I106& I107STARTCheck X100 is OK?Replace I101Replace

6.3. NO DISPLAY NTSCTVYPb Pr S-VIDEONoNoReplace I106NoReplace LVDS WireNoCheck inverter wire frompower board to panel is OK?Replace Inverter WireNoR

DTVCheck Inner RF cable isOK?Replace Inner RF cableCheck HDMI Cable is wellconnected ?Connect the cableHDMINoNoCheck I807 has outputsignal at RP80~RP

SPDIF(Optical)CD4052(Audiosw.)DDRSDRAMRFSWITCHFlashAIRPC(D-Sub)AD12250(A/Dconverter)HDMI 2AD8256(AudioAmp.)MT5112(Demod.)LCD ModuleNTSCHDMISWITCHAV(CV

8. Schematic Diagrams 8.1. DC POWERAUIO IN/OUT GND DIGITAL GNDBack Light circuitInitial pull upDC INPUTBACK_LIGHT PWMTURN OFF SIGNALSHi EnableHiEnable

Parameter Specification LCD Type a-Si TFT Active Matrix Wide Color, Transmissive Mode, Normally Black LCD Interface 1-Channel LVDS Resolution (Nativ

8.2. DC TO DCThis voltage must be arround 1.95v.ADCV18AVFE_GND1VFE_GNDVFE_GNDAV18AAV33AVFE_GND1VFE_GNDLVDS_GNDDV18AASB33ALVDS_GNDSB33ALVDS_GNDASB18ASB

8.3. MT8202 PBGA 388MTK modifyB+ & GNDAUTO_FINE_TUNELVDS DATAVGAYPbPrSAVNTSCAUDIO OUTI2S SWITCHHDMI or ATSC AVDDRFLASH MEMORYMTK modifyVGAHSYNC_1F

8.4. MT8202 DDR MEMORY & FLASHTSOP 48 pinVREF DECOUPLINGCLOSE TO 8202 PINPULL HIGH D1V25 ARRAY RESISTORDECOUPLING CAP ON THE BOTTOM SIDE.DDR DECOU

8.5. MT8202 ANALOG DECOUPLINGV2NORMAL ANALOG POWERNORMAL AUDIO ADC / DAC POWERV2STANDBY ANALOG POWERNORMAL VIDEO ADC POWERNORMAL VIDEO DAC POWERMTK mo

8.6. MT8202 DIGITAL DECOUPLINGMT8202 DIGITAL POWER & DECOUPLINGSB18A5VSBSB18ADV18ADV33ASB33AC2930.1UC0603C2890.1UC0603C2883300PC0603C3010.1UC0603C

8.7. COMBO TUNERGLOBAL SIGNALTUNER INTERFACEROUTE SYMMETRICALLYClose to TunerNTSC CVBSSIF (4.5MHz)AIR INPUTCABLE INPUTTO DTVS205CH201ATUNER ANALOG OUT

8.8. AUDIO/VIDEO IN CIRCUITFROM TunerFROM AV BOARDTHIS PAGE NEARLY ICTO MT8202DELAVPR0PAVPB0PVFE_GND1AVCVBS1TUMPX1PR0+Y0-AVCVBS0VFE_GND1PR0-CVBS1AVSOY

8.9. INPUT SOURCEYPBPR AUDIO INS-VIDEO/AV INS-VIDEO/AV AUDIO INYPBPR/AV Input.YPBPR VIDEO INYPBPR/AV/SAUDIO Input.SVIDEO Input.SY0_INAVSC0YPBPR0L_INA

8.10. HDMI INPUT-MT8293NC if AVCC18 from regulatorV2I106/Y25ࢮࠩMTK modifyMTK modifyACTIVE LOWI2C ADDRESSDATA2-HDMISD2VI8VCC18HDMICENHDMIHSYNCVI14CCIR_G

8.11. HDMI SWITCHOUTPUT ENABLE ACTIVE LOW.HDMI1HDMI2HDMI3S1 S2 S3HI XX XXH1 H2 H3XX HI XXXX XX HIHDMI_SRC1_TMDS_D2PHDMI_SRC3_TMDS_D2P

2. Video Built-in A/D converter shall provide analog to digital converter for this product. Input Parameter Specification CVBS Characteristi

8.12. ATSC INDEXGNDGLOBAL SIGNALPOWER SUPPLYPOWER SUPPLYTUNER POWERMT5112 POWERMT5112 POWERMT5351 POWERMT5351 ANALOG POWERMT5351 DDR POWERMT5351 POWER

8.13. MT5112 ASICGLOBAL SIGNALCLOSE TO MT5112Digital 3.3V Bypass CapsAnalog 3.3V Bypass CapsDigital 1.8V Bypass CapsTUNER INTERFACETS INPUTMODIFIED IN

8.14. ATSC POWERPOWER SUPPLY +3V3 FOR MT51121.25 x (1+0/100) = 1.25VPOWER SUPPLY +1V2 FOR MT5351POWER SUPPLY +3V3 FOR MT5351 (ANALOG)POWER SUPPLY +2V5

8.15. MT5351 ASICDIGITAL VIDEO OUTPUTFLASH INTERFACEANALOG PARTUART (RS232)TEST PURPOSEJTAG PORTGLOBAL SIGNALTS INPUTCLOSED TO MT5351DDR MEMORYAUDIO I

8.16. MT5351 DDR MEMORYBYPASS CAP. FOR DDRDDR#1 DDR#2CLOSED TO DDRDDR MEMORYCLOSED TO MT5351CLOSED TO DDRCLOSED TO DDRCLOSED TO MT5351FOR DDR#2CLOSED

8.17. MT5351 FLASHFOR SOFTWARE LINKUART (RS232)JTAG PORTNOR FLASH #0FLASH INTERFACEGLOBAL SIGNALTRAP CIRCUITSOFTWARE DEBUG PORTCLI OUTPUTJTMSPDA13U2TX

8.18. MT5351 PERIPHERALLEFT SIDETOP SIDEBOTTOM SIDEBOTTOM SIDELEFT SIDERIGHT SIDEGLOBAL SIGNALLEFT SIDEANALOG PARTRIGHT SIDETOP SIDEADDMTKMODIFIEDHIGH

8.19. AUDIO SWITCHS-VIDEO/AV AUDIO INYPBPR AUDIO INVGA AUDIO INAUSW1_2YPBPR0_LAV0SY0L_INYPBPR0L_INAUSW1_1YPBPR0_LAUINRVGAL_INYPBPR0L_INSW1S2VGA_RAV0SY

8.20. AUDIO ADCAUDIO ADCPULL DOWN FOR LJAOLRCKA_IN_LAUINLAOBCLKADCM0ADCVLADCM0AOLRCKADCM1ADCVLAUINRA_IN_RADCM1AOMCLKADCRST_1AOMCLKAOBCLKADCVLADINGNDAA

8.21. AUDIO DACBYPASS AUDIO OUTPUTTO ERAPHONE OUTPUTTP02ࢮࠩADDMTK modifyMTK modifyRCA JACK 1*2 layo٥utARALGNDAAUDIO_OUT2_LAUDIO_OUT2_RGNDAOP1VREFARALO

4. Electrical The following table defines the electrical specification of this product. ELECTRICAL SPECIFICATION Power Input Voltage Range 100

8.22. VGA IN & PC AUDIO INNEARLY VGA CON NEARLY ICVGA INPC DDCVGASOGVGASCL_INGNDAVGAVSYNC_1GNDAGREEN-REDPCRXDVGAR_INVGA_PLUGPWRDLSW1REDRED-VGASCL_

8.23. AUDIO AMPPOP NOISE HAVE TO DROP 3V3 FIRST THEN 12V DROP DOWN OK.L+L-R+R-HI EARPHONE MODETHEN MUTE AUDIO AMP.YC124RTYC124RTYC124RTYC124RTHPLHP-SP

8.24. IR & KEYPADEXCHANGEMTK modifyױאޏֺለ൷२ऱstandby 3.3V DV33B standشbyழᄎ޲ሽRED_LEDGREEN_LEDGPIO15GPIO11GPIO14GPIO16GPIO13GPIO10GPIO14GPIO13GPIO11UP

8.25. PANEL INTERFACECHANGEˉ˔AN[0..3]AP[0..3]LVDS_GNDGPIO2CLK1-CLK1+LVDS_GNDGPIO2LVDS_GNDAP3CLK1+AN2AN3AN0AP0AP1AP2CLK1-AN1LVDS_GNDLVDS_GNDLVDS_GNDGPI

8.26. SYSTEM EEPROMSYSTEM EEPROMRESET# CircuitH : Normal DownloadL : Write Protect EEPROMSYSTEM EEPROMNEW USB DOWNLOAD I/FGPIO4SYSROMWPSCLSDADLSW2TXDP

9. PCB Layout Diagrams 9.1. MAIN PCB TOP VIEW ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 82

9.2. MAIN PCB BOTTOM VIEW ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 83

9.3. CON PCB TOP VIEW ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 84

9.4. CON PCB BOTTOM VIEW ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 85

9.5. IR PCB TOP VIEW ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 86

Memory recall Set user settings to factory preset value Treble Adjust the Hi Frequency levels Bass Adjust the Low Frequency levels Balance Adjus

9.6. IR PCB BOTTOM VIEW ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 87

9.7. SWITCH PCB TOP VIEW ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 88

9.8. SWITCH PCB BOTTOM VIEW ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 89

10. Exploded View And Exploded Parts List ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 90

ViewSonic Corporation Confidential - Do Not Copy N4251w-1M 91

ViewSonic Model Number: VS11502-1MRev: 1aSerial No. Prefix: QEMItem ViewSonic P/N Ref. P/N Q'ty1 N/A 2024274502P FRONT BEZEL JC429FE ABS94HB

Serial No. Prefix: QEM Rev: 1aItem ECR/ECN ViewSonic P/N Ref. P/N Location Universal number#1 Power Cord AC A-00005362 2427130046P P951 2 Remote Cont

ViewSonic Model Number: VS11502-1MRev: 1aSerial No. Prefix: QEMItem ViewSonic P/N Ref. P/N Location Universal number# Q'ty1 N/A 2024274502P FRONT

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription82 N/A 2055135178P LABELN4251W VS11502-1M AUO USA 6P50 183 P-00008063 20130

Item ViewSonic P/N Ref. P/N Location Universal number# Q'tyDescription168 N/A 2346110496P CAP,CHIP 125'CCS 0603/X7R/50V 0.1u K T C179