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Safety precautions 

1. Instructions

 

Be sure to switch off the power supply before replacing or welding any components   or 
inserting/plugging in connection wire Anti static measures to be taken (throughout the entire 
production process!): 
a) Do not touch here and there by hand at will; 
b) Be sure to use anti static electric iron; 
c) It’s a must for the welder to wear anti static gloves. 
Please refer to the detailed list before replacing components that have special safety requirements. 
Do not change the specs and type at will. 

 

2. Points for attention in servicing of LCD 

2.1 Screens are different from one model to another and therefore not interchangeable. Be sure to 
use the screen of the original model for replacement.   
2.2 The operation voltage of LCD screen is 700-825V. Be sure to take proper measures in 
protecting yourself and the machine when testing the system in the course of normal operation or 
right after the power is switched off. Please do not touch the circuit or the metal part of the module 
that is in operation mode. Relevant operation is possible only one minute after the power is 
switched off.   
2.3 Do not use any adapter that is not identical with the TV set. Otherwise it will cause fire or 
damage to the set.   
2.4 Never operate the set or do any installation work in bad environment such as wet bathroom, 
laundry, kitchen, or nearby fire source, heating equipment and devices or exposure to sunlight etc. 
Otherwise bad effect will result.   
2.5 If any foreign substance such as water, liquid, metal slices or other matters happens to fall into 
the module, be sure to cut the power off immediately and do not move anything on the module lest it 
should cause fire or electric shock due to contact with the high voltage or short circuit. 
2.6 Should there be smoke, abnormal smell or sound from the module, please shut the power off at 
once. Likewise, if the screen is not working after the power is on or in the course of operation, the 
power must be cut off immediately and no more operation is allowed under the same condition.   
2.7 Do not pull out or plug in the connection wire when the module is in operation or just after the 
power is off because in this case relatively high voltage still remains in the capacitor of the driving 
circuit. Please wait at least one minute before the pulling out or plugging in the connection wire. 
2.8 When operating or installing LCD please don’t subject the LCD components to bending, twisting 
or extrusion, collision lest mishap should result.   
2.9 As most of the circuitry in LCD TV set is composed of CMOS integrated circuits, it’s necessary 
to pay attention to anti statics. Before servicing LCD TV make sure to take anti static measure and 
ensure full grounding for all the parts that have to be grounded.   

 

2.10 There are lots of connection wires between parts behind the LCD screen. When servicing or 
moving the set please take care not to touch or scratch them. Once they are damaged the screen 

Attention: 

This

 

service manual is only for service personnel to take reference with. Before 

servicing please read the following points carefully. 

 

 

Summary of Contents for LC-27FB26

Page 1: ...LCD TELEVISION LC 27FB26 ...

Page 2: ...tware upgrading Working principle analysis of the unit Block diagram IC block diagram Wiring diagram Identification criteria for the bright spot and dark spot of the LCD screen Troubleshooting guide Schematic diagram APPENDIX Exploded View 1 3 8 14 15 16 26 27 28 37 ...

Page 3: ... will result 2 5 If any foreign substance such as water liquid metal slices or other matters happens to fall into the module be sure to cut the power off immediately and do not move anything on the module lest it should cause fire or electric shock due to contact with the high voltage or short circuit 2 6 Should there be smoke abnormal smell or sound from the module please shut the power off at on...

Page 4: ... of picture residue on the screen as commonly called ghost shadow The extent of the residual picture varies with the maker of LCD screen This phenomenon doesn t represent failure This ghost shadow may remain in the picture for a period of time several minutes But when operating it please avoid displaying still picture in high brightness for a long time 3 Points for attention during installation 3 ...

Page 5: ...utton to decrease the volume to 0 then press 9876 to enter level one factory menu Press CH and CH to select adjustment page then press OK Check DDC and FLASH To produce digital board and analog board All testing Adjust white balance Connect with central signal source then check each function of TV such as station missing analog control etc check the output of headphone and speaker Input AV SVIDEO ...

Page 6: ...nel TMIING select a support format of VGA enter white balance adjustment page of factory menu select cool color temperature of item fixed WBGG_VGA to 128 adjust WBRG_ VGA WBBG_VGA let the color coordinate of third level on the right be 270 283 at 400nits fixed WBGO_VGA to 128 adjust WBRO_VGA WBBO_VGA let the color coordinate of third level on the left be 270 283 at 5nits The brightness of 400nits ...

Page 7: ...469 70 086 28 322 IBM 2 640 X 480 31 469 59 94 25 175 IBM 3 640 X 480 37 861 72 809 31 5 VESA 4 640 X 480 37 5 75 31 5 VESA 5 640 X 480 43 269 85 008 36 VESA 6 800 X 600 35 156 56 25 36 VESA 7 800 X 600 37 879 60 317 40 VESA 8 800 X 600 48 077 72 188 50 VESA 9 800 X 600 46 875 75 49 5 VESA 10 800 X 600 53 674 85 061 56 25 VESA 11 1024 X 768 48 363 60 004 65 VESA 12 1024 X 768 56 476 70 069 75 VESA...

Page 8: ...ybe there is interference between antenna and power supply line Please try to separate them in a longer distance Maybe the shielded layer of signal wire is not connected properly to the connector There appear streaks or light color on the screen Check if interfered by other equipment and if interfered possibly by the equipment like transmitting antenna non professional radio station and cellular p...

Page 9: ...Check if the TV set can receive input signal The signal is not correctly identified and VGA format is beyond the specified scope Remote control cannot work properly Check if the batteries are installed in the reverse order Check if the battery is effective Check the distance or angle from the monitor Check if there is any obstruct between the remote control and the TV set Check if the remote contr...

Page 10: ...uter and TV set The cable must be a female to female RS 232 cable and the line is TXD to RXD and RXD to TXD cross link It s popular for PC to PC connection 2 If the computer has no RS 232 serial port e g Notebook PC you needs a additional USB to serial port cable ...

Page 11: ...the update tools iDev exe to the path you want to do it and double click it 4 Select setup menu 5 Confirm the Serial port is right Base on the port which using for update And set the band rate to 115200 default ...

Page 12: ...mage path menu 7 Confirm it s the right file 8 If it s not right Maybe you didn t select it before click the button to select ecc file Sometimes the image file you got it will be rar or zip zip file needs unzip it first ...

Page 13: ...11 9 You also can click the setup button to select and config but please don t select the red one update boot sector 10 Then click the down button ...

Page 14: ...12 11 You can see the waiting window 12 Then power off then on the TV set 13 After download it will be burning ...

Page 15: ... 14 Last it will be finished 15 Press the IR locate keypad power key and holding for several second to force power off TV set then power on again It would be ok now If it s failure you can try once again ...

Page 16: ...d stereo decoder fed to ZR39660 for information source decoding in the format of standard serial TS stream HD video signal via decoding to A D conversion and OSD superposition at last send to LVDS drive level for PDP panel HD audio signal via decoder built in ZR39660 resumed to multi channel sound of Dolby AC 3 at the same time output data stream of I2S format and S PDIF data stream Audio data of ...

Page 17: ...0 BGA400 2X16MX16 DDRAM HS VS CLK YPBPR2 YPBPR1 SN3257C LVDS M29W320E Panel FLASH HDMI IIS IN TS CVBS_TV HEF4052BT CVBS2 CVBS1 S_Y S_C SN3253C AV1 AUDIO AV2 AUDIO YPBPR1 AUDIO YPBPR2 AUDIO PC AUDIO D A CS4344 R2S15102NP NJW1109 Loudspeaker Earphone IIS OUT CVBS Y C FQD1236 MK5 LC 27FB26 V1 0 R2S15900SP JEPICO j L003 Block diagram ...

Page 18: ...16 IC block diagram 1 ZR39140 ...

Page 19: ... Chroma In W3 Video Front End Common Mode Reference 4 Analog Video Output K18 Composite Data Output CVBS J20 Blue Pb Pixel Data Output J18 Green Y Pixel Data Output J19 Red Pr Pixel Data Output 5 Audio I O R2 Audio Clock R3 Bit Clock P3 Left Right Channel Selector U2 Serial Audio Data Input T2 Serial Audio Data Output V1 IEC958 Format Out 6 LVDS Panel Interface B20 C19 Output Clock Pair E18 F17 Ou...

Page 20: ...ned to produce sharp well defined coloration in personal computer LCD monitors and LCDTV screens as well as dot matrix displays in rear projection TVs PDPs and other devices The image enhancement functions built into the j L003 use a proprietary color management technology that makes it possible to produce images that are closer than ever to nature The j L003 also includes black white stretch brig...

Page 21: ... Signal OUTPUT 3 I O CONTROL 148 RESET 151 SMMRSE 156 ADID0 157 ADID1 3 CAS220 CS The CAS 220 CSO is a multi standard demodulator and decoder for terrestrial and digital cable TV reception It is designed to support 8 VSB Vestigial Side Band in full compliance with ATSC Digital Television Standards ITU T J 83 Annex B and OpenCable Out of Band Signaling The CAS 220 CSO also demodulates analog BTSC a...

Page 22: ...clock from host 20 I2C data from to host 93 94 Differential input for IF 96 97 Differential input for SIF 63 Digital Sound Word select L R select 65 Digital Sound Serial data output 66 Digital Sound Serial clock 17 30 46 62 74 82 84 Power Supply 3 3V 5 9 22 37 53 69 75 78 86 87 99 Power Supply 1 8V 6 7 15 23 33 35 45 55 60 70 73 76 77 81 83 85 88 91 92 95 98 Ground ...

Page 23: ... Pixel Clock Synthesizer The triple ADC support 12 110 MHz Sampling Rate It integrated 5 bit pixel clock phase adjustment for precise sample timing control It s Output support 4 2 2 Format Mode and it can Pin Compatible with AD9883A Block diagram of MST9883 is flow ...

Page 24: ...reen analog input 38 External Clamp Input 30 Horizontal SYNC Input 31 Vertical SYNC Input 29 Hold PLL Frequency do not track HSYNC 56 Serial Interface clock 57 Serial Interface data pin 55 Serial interface address pin 70 77 Red output data 2 9 Green output data 12 19 Blue output data 67 Output data clock 66 HSYNC output 64 VSYNC output ...

Page 25: ... 61 63 68 80 Ground 5 R2S15900SP R2S15900SP is an audio signal processor It has MUTE and Volume Tone control It can support 5 input selector Pin descriptions of R2S15900SP 2 27 AV1 AUDIO INPUT L R 3 26 AV2 AUDIO INPUT L R 4 25 DTV AUDIO INPUT L R 5 24 EAR PHONE L R 6 23 AV OUT L R 11 19 AUDIO OUTPUT L R 17 18 I2C SDA SCL 28 Power Supply 12 Ground ...

Page 26: ...put stage 2 3 STBYL I Stand by control pin When this is L circuit current is reduced There is the pull down resistor 50K ohm typ 4 PWM1 I PWM input pin 1 for phase compensation 5 IN1 I Analog input 1 The gain is depended on the external resistance 6 CBIAS I O A capacitor is connected so that it may not be influenced of power supply change Ripple Filter 7 ROSC I Control pin for PWM carrier frequenc...

Page 27: ...ompensation 13 MUTEL I Mute control pin When this is L it becomes mute status 14 VD2 Power supply pin for power output stage 2 15 OUT2 O Power Output pin 2 16 VS2 Ground pin for power output stage 2 17 HB2 I O Capacitor connection pin for bootstrap 18 DVDD O Built in power supply pin for internal digital block 19 HB1 I O Capacitor connection pin for bootstrap 1 20 VS1 Ground pin for power output s...

Page 28: ...7 L27W18 09 boa Video rd 67 32 B 6 F 18 40 To speaker Power switch Pin3 4 left audio channel Pin1 2 right audio channel To speaker LVDS 30 pins 2pins 4 pins 3 pins 7 pins 3 pins 4 pins XC02 XB01 XB03 XC01 X801 X805 X602 X802 X102 X103 X222 X221 X101 X104 X502 X503 XA01 CN2 X 0 1 8 X 1 1 3 X112 X804 3 X60 XA50 X605 X291 X293 X501 Wiring diagram 203 L27FB18 01JL 26 ...

Page 29: ...m 10mm 5mm Total defected point 8 7 5 4 Notes 1 Definition of defected point bright spot dark spot It is identified as a defected point if its area exceeds 1 2 of a single picture element R G B 2 Definition of bright spot It is identified as a bright spot if it is bright in the state of dark field and its bright size remains unchanged 3 Definition of dark spot It is identified as a dark spot if it...

Page 30: ...o picture abnormal of PC YPrPb and YCrCb f Failure with N104 which may lead to picture abnormal of TV AV1 AV2 S VIDEO g Failure with N803 N805 N806 which may lead to picture abnormal in all channels Begin A red indicator lights Check power board button board and power cord A blue indicator lights Check if the pin1 of X602 in data processing board is high level 5V check V660 V661 No No Yes turn the...

Page 31: ...ower board No sound No picture Power board problem Refer to 3 checking procedure Refer to 4 checking procedure No Yes Check the power board With picture but no sound Check if the voltage of sound amplifier of X106 in analog board is normal No Yes Check if the pin5 pin11 of N111 inputs signals Check N111 and their peripheral circuit Check N103 NB05 and their peripheral circuit Yes No ...

Page 32: ...Yes No If there is no picture in all channels Check if the crystal in data processing board starts DDR clock and DDR SDRAM are normal Yes No Check N108 and its peripheral circuit Refer to 6 7 8 9 10 11 12 checking procedure Refer to 5 checking procedure Check N801 N802 DDR and their peripheral circuit and power supply Yes No ...

Page 33: ...7 30 of X801is high level Check if the power supply of L801 L802 are normal Check if pin3 5 26 of N806 output H V SYNC and clock Check the peripheral and power supply of N801 N802 DDR of data board Yes No Check the peripheral and power supply of N806 Check if pin34 65 66 of N803 output H V SYNC and clock Yes No Check the peripheral and power supply of N803 Check the peripheral and power supply of ...

Page 34: ... and the circuit from AV terminal to N104 Check the periphery circuit from XC02 to N801 Check N104 and its periphery circuit Check if C105 and C138 input signals Yes No Yes No Check if pin13 3 of N104 outputs signals Check N108 and the circuit from S terminal to N104 Check the periphery circuit from XC02 to N801 Check N104 and its periphery circuit ...

Page 35: ...ically Check if pin11 of TUNER226 output signals Yes No Yes No Check if pin13 of N104 outputs signals Check TUNER226 power supply and the peripheral circuit Check the periphery circuit from XC02 to N801 Check N104 and its periphery circuit Check if pin6 7 of TUNER226 output signals Yes No Yes No Check if the crystal of N228 20MHz is normal Check TUNER226 power supply and the peripheral circuit Che...

Page 36: ... signals Yes No Yes No Check resistor rows RA63 RA68 Check NA51 and peripheral circuit Check NB01 NB02 and the circuit from X807 X808 to N808 Check NB07 and peripheral circuit Check if pin4 7 9 of NB07 output signals Yes No Check if pin64 66 67 of NA51 are normal Yes No Check resistor rows RA63 RA68 Check NA51 and peripheral circuit Check NB03 NB04 and the circuit from X807 X808 to N808 ...

Page 37: ...7 a No power supply Check DETECT NA04 and its peripheral circuit Yes No Check if signals of RA18 RA25 are normal Yes Check N801 and its peripheral circuit Check the connection to HDMI socket NA04 and its peripheral circuit Does AC voltage at C505 No power supply Does DC voltage at C528 150 370V Check if X501 FU501 is properly inserted Check D502 R531 D508 Check if the 15V DC of N501 pin13 Check N5...

Page 38: ...t No DC voltage output Check if DC voltage of C536 is 3 3V 5V Check if DC voltage of V505 B is 24V Check if DC voltage of C537 is 24V Check FU502 Check D515 or T501 Check main board Check N502 or peripheral circuit N N N Y Y Y ...

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Page 50: ...APPENDIX Exploded view LC 27X26 ...

Page 51: ... board assy 14 780 X26WH 120 Back cabinet 15 808 10981 120 Back cabinet cover right 16 808 10980 120 Back cabinet cover left 17 808 10982 120 Rotor cover 18 615 10675 2F0 Stand assy 19 615 20575 00 Speaker assy 20 Analog board assy 21 trans connect board assy 22 804 20468 00 Connecting piece of speaker box 23 IR receice board 24 808 10970 120 AV baffle bottom 25 808 20405 212 Active Decorative pie...

Page 52: ...603 L27FB26 12 Ver 1 0 ...

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