2019 Led Lcd T-2-2

LED/LCD TV T-CON & Screen Panel Repair Guide Try to replace the old T-con board EEPROM IC to the new T-con board there, but still no help.

Finally found that it same as the LG T-con board, it has a special place to modify their setting through hardware method. That is to change their resistor position as change their T-con board setting. Refer to photo below:

• Original resistor position (Display Upside Down): R459, R458, R451, R455, R453 • After changed resistor position (Display back to normal position): R459, R458, R452, R455, R454 After changed these SMD resistors position, the TV display was back to normal now.

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How to Solve Display Upside Down Problem in Universal LCD/LED TV Mainboard

When the TV is complaint upside down (or after replace Universal Mainboard) problem, if this is a Universal Mainboard, they have two methods to solve this problem. 1) Make adjustment in Factory Setting - Some universal mainboard built in a feature call it as “Mirror Mode” or similar function name feature. So we can go there to adjust their setting and the display will back to normal position. For Example: 6M48/6M182/6M30 Series Universal Flat TV Mainboard # After login in the TV Factory Setting, go to “Panel Adjust” and select the “6M30”. (Refer to 6M182.21B Universal Mainboard)

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Inside the 6M30 Adjust menu, found the 6M30 “MIRROR MODE” button. This “MIRROR MODE” has 4 selections: 1,2,3,4. Each control Upside Down and Left Right reverses. From here you can choose which one is suit the TV screen position. So the display upside down problem can be solving it easily.

2) Replace or Upgrade their Universal Mainboard Firmware - Some of the universal mainboard, one model/part number mainboard, but it has two types of firmware. One is normal position firmware, another one is upside down firmware. For example, some of the V59 series universal mainboard. So if you’re facing the display upside down problem in universal mainboard but their Factory Setting not provided the Mirror Mode or similar function to control the display position, then you

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LED/LCD TV T-CON & Screen Panel Repair Guide need to find out another same manufacturer and spec firmware, also confirm that is a upside down firmware. After that programmed or upgrade the firmware into the Mainboard or their flash memory IC there. - With this method, you can solve the Universal Mainboard upside down problem easily. Before that, lots of the TV repairer when they facing these type of Universal LCD/LED TV Mainboard, they don’t know how to do it. So they just replaced a whole Mainboard or return back to customer and said that’s the panel, not worth to repair it. But when you know how to repairing it, so it will not the problem to repair display upside down problem in Universal Mainboard. - If the above method also can’t solve the display upside down problem, please refer to this ebook Part-3 & 4 of troubleshooting & repairing display upside down problem. Because some of the T-con board/section has design a feature to control the display position.

Notes: If the above TV setting after changed is back to normal display, but after restart the TV, it’s still same problem like before. Then you need to checking Mainboard EEPROM, Flash Memory IC and their voltage supply (make sure that voltages are normal and stable).

Extra Notes: Some of the Universal Mainboard built in above 10 types of LCD/LED Panel “Firmware” (not the settings). So this type of Universal Mainboard no need to programmed their firmware when replace different LCD Panel. Some of them can use the USB thumb drive to upgrade their firmware without the ISP Programmer. But if their main firmware corrupted, then you also need to use ISP Programmer to transfer or copy the firmware from a good mainboard EEPROM or Flash IC. So the ISP Programmer is a must have tool to repair TV or other electronic devices.

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Display Left Right Reverse Problem Solved T-con Board: Sharp 4224TP CPWBX RUNTK DUNTK Panel: Sharp 42 inches Panel

This Sharp LCD Panel has a common fault of display left half and right half was reversed. Please refer to the photos above. This TV even re-programming their Mainboard firmware also can’t solve the problem. So confirm the problem was in the T-con board there. But this part number of T-con board EEPROM firmware is not available. So it is hard to repair it or maybe need to replace a new or working T-con board to give it a try. http://www.lcdrepairguide.com/tcon-panel/

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LED/LCD TV T-CON & Screen Panel Repair Guide Fortunately found this model of T-con board (Panel) has a common fault of this symptom. And the manufacturer also created the solution or service bulletin to repair this T-con board. The method is easy just solder a wire to shorted the smd inductor nearby the LVDS connector. Please refer to the photos below. After that this TV display problem solved!

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White Screen Problem on V315B3-C04 T-con Board T-con Board: V315B3-C04 Panel Model: V315B3-L04 This T-con board has using in lots of brands and model LCD Tv, for example Sony, Hisense, Konka and etc.

This LCD Panel V315B3-L04 has a common fault that is “White Screen’ problem. This is because of the V315B3-C04 T-con Q2 (A18E, P-channel MOS) was shorted. When this LCD Panel with white screen problem measures their VAAP (or calls it as VDA) is 0V. Power of the TV, using Ohm meter to measure the VAAP point to GND is about 2 ohm only! That’s mean some of the VAAP circuit component/s is shorted. After checking VAAP circuit found the Q2 was short circuit. Remember! Please don’t direct replace the Q2 and power on the TV. Because it maybe will short or burn the Q2 or maybe take some time it will come back again with the same symptom. This is because of their LCD Pane l design bug! Their Source PCB and above metal shield not put an isolated pad in between

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LED/LCD TV T-CON & Screen Panel Repair Guide them. So it will easily Source PCB components touch the metal shield and shorted T-con board. So insert a thin plastic pad or any insulated material to isolate the Source PCB and their above metal shield. Remember to put insulated of both left and right side Source PCB. After modify, this LCD Panel can last long to use.

Note: This T-con board VAAP to Ground good ohm values is about 26Kohm or above.

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No Display or Grey Screen - Common Fault on LG 370WX4-SLA1_(6870C-0158A) Panel: LG 370WX4-SLA1 T-con Board: 6870C-0158A Symptom: No display or grey screen (no display but backlight lit)

This LG 370WX4-SLA1 has a common fault in its T-con board. The common fault symptom is No Display or Grey Display (because the backlight is lit). After checked the T-con board found that VHGM no voltage, but VGH has about 26V.

Found the U7 IC has VGH voltage input, but their VGHM is no output. After replaced U7 (RT8901), the TV No Display problem solved.

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LG 470WU5-SLA1(6870C-0140B) No Display Problem Solved T-con Board: 6870C-0140B LCD Panel: LC470WU5-SLA1

A 47 inches LCD TV came with complaint no display problem. After power on the TV, TV sound ok and backlight lit. So suspect the T-con board problem. After checked the T-con, found their VGH voltage abnormal just about 2V only.

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Trace the VGH circuit line and found the SMD R128 (82ohm) was opened circuit. After replaced this resistor, the Tv can show the display perfectly. Below is the VGH waveform for this T-con.

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AUO T460HB01 V0 (46T12-C01) T-con Board with Randomly No Display Problem T-con Board: AUO T460HB01 V0 / 46T12-C01 Tv Model: TCL LE468810 LED TV

This T-con Board has a common fault as randomly no display. Actually this type of symptom is very hard to troubleshoot. Unless we have all the working PCB boards use one by one to swap and test. Finally found the problem was their T-con board defective.

When the TV no display, checking their T-con and found that Q201 pin S (Source) is about 15.5v. Pin G (Gate) is 13.2v, but the pin D (Drain) is 0v, no output! After replaced this Q201 with AO3041A on T-con board, this TV is back to working now.

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How to Solve Samsung LCD TV Oil Painting Display Problem The customer bought in a LCD TV with the symptom like display oil painting. You can refer to the photo below:

This LCD TV didn’t have any logo in front of the TV cover and the rear cover also no any tv manufacturer details or the model too. But the customer said it is a Samsung LCD TV. After dismantle this LCD TV, their PCBs are use as photo below:

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LED/LCD TV T-CON & Screen Panel Repair Guide This LCD TV is using a Universal LCD/LED TV Mainboard, not the Samsung mainboard as usual we look inside the Samsung Tv. This mainboard part number is: VS.T811_V2.1. The photo of this universal mainboard:

This universal mainboard was using in many OEM brands LCD & LED TV. But this mainboard has a common fault it was the symptom of “Oily Painting Display” problem or Display Distortion problem on the screen.

Normally this symptom was causing by the TV Panel setting problem. Because of this universal mainboard(VS.T811_V2.1) can support several model panels for LCD/LED TV, so it has panel setting inside their Factory Setting. Use the Universal Mainboard TV remote control and press the “SOURCE” button, after that press buttons 2, 0, 8 (within 3 seconds) and it will show the Factory Setting page on the screen.

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Choose the “Panel Adjust” button, inside there to select “Ti Map 10 Bit T-=1”. Exit the factory setting and restart the TV. The TV is back to normal now.

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LED/LCD TV T-CON & Screen Panel Repair Guide Yes! This Tv is showing the Samsung logo on the screen. This is a clone or copycat Samsung LCD TV!

This universal mainboard is using in many OEM LCD/LED TV. So you can learn this method to repair different OEM brands LCD/LED TV now.

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Samsung Display Distortion (Oily Painting Display) Repair Solution Many Samsung main boards are designed to support multiple models. Each board comes with a simple set of instructions that will generate a picture. The Option Bytes are programmable to support different screen sizes, different feature sets or even different panel types. If a new main PCB is installed the option bytes must be verified to ensure proper operation.

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Option Bytes data can be obtained from the service manual. Each model and panel type must be matched to ensure proper operation. These are examples of incorrect option byte settings. The picture on the left not only shows incorrect picture color but the picture is upside down.

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The above display problem need to login to their Option Bytes menu to make an adjustment there to repair this display problem. Here are the steps to login: 1) Using the customer remote control enter [MENU] + [1]+[8]+[2]+[POWER] 2) Enter into the Option Bytes menu

There are a variety of test patterns that can be used to isolate panel failures from a Mainboard issue. There are under the FBE or Enhancement sub menu. Here are the steps to login: 1) Using the customer remote control enter [MENU] + [1]+[8]+[2]+[POWER] 2) Enter into the Option Bytes menu 3) Enter the code listed below: - 540 series and lower 0000 + Exit - 550 series and higher 0214 + Exit

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LED/LCD TV T-CON & Screen Panel Repair Guide 4) Exit the option byte menu, the grayed out option (FBE3 or Enhancement) should be available now (If the option still isn’t available re enter the code). 5) Scroll down and enter the FBE or Enhancement option. 6) PATT SEL should be the first option 7) Scroll through the test patterns If these test patterns display without error the problem is not with the Panel or T-con/FRC boards. Note: The patterns are not available on some lower end models TV.

T-con Board Failure Modes If the T-con board failures can be all over the screen or localized. T-con board failures can cause half the screen to go black of full white. T-con board defects do not go away with content or connection. If the problem disappears when the input s changed it is not the T-con board. If the problem completely disappears with a darker or brighter scene the problem is not the T-con board.

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LED/LCD TV T-CON & Screen Panel Repair Guide FRC Board Troubleshooting The FRC board can be tested by accessing the FRC Test Pattern under the control submenu of the service mode. Both of the FRC patterns are generated on the FRC Board. If the test patterns are displayed without error the problem is before the FRC board, either the Mainboard or the video source. Additionally if the FRC board cannot communicate with the Mainboard the front panel LED will flash at startup.

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How to Solve Display Distortion (Oily Painting Display) Problem in Universal LCD/LED TV Mainboard

1) T.VST29.03 / T.VST59S81 Series Universal Mainboard After login to the Factory Setting menu, go to “Panel Config”. After that, select the “LVDS MAP” and change its values from 0 ~15 until the screen display back to normal. After change the LVDS MAP setting and logout Factory Setting. The TV Display Distortion (Oily Painting Display) problem solved.

2) 6M48/ 6M182/6M30 Series Universal Mainboard As usual, after login to their Factory Setting, go to select “Panel Adjust” and then select “LVDS MAP”.

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Change the LVDS MAP values from 0~15 through control the remote controller left & right buttons, until the normal or good display present. Normally for AUO55LED & AUO65LED using LVDS MAP “0 or 15” is ok. ChiMei(CMO) 65LED panel is using “9 or 10” is ok. Other brands panel manufacturer, you can try to check one by one.

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LED/LCD TV T-CON & Screen Panel Repair Guide 3) MST6M18-V2 Universal Mainboard After successfully login to the Factory Setting, select “Special Set” and select “LVDS TI MODE”. Press the Left and Right arrow buttons to adjust or change their setting. If still not help, then go to select their “LVDS Swap Polarity” to change to 6 Bits, 8 Bits or 10Bits mode till the display back to normal (Especially the display also has Ghosting problem).

Notes: If the above TV setting after changed is back to normal display, but after restart the TV, it’s still same problem like before. Then you need to checking Mainboard EEPROM, Flash Memory IC and their voltage supply (make sure that voltages are normal and stable).

How to Repair LCD TV Symptom with Blue Screen and Vertical Bars Brand: Hisense TLM-3233D LCD TV Symptom: No Display but Blue Screen with Two Vertical White Bars

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LED/LCD TV T-CON & Screen Panel Repair Guide When power on this lcd tv, the screen show no display but blue screen with two vertical white bars. The two vertical white bars will flash but no any content inside. The LCD TV can hear the sound and remote control to change channel properly. Try other video signals input like AV and PC also same results. Even try to call out the OSD menu also same problem too. Since the LCD TV cannot show the OSD menu and the TV got sound and change channel properly, so that the mainboard is normal. After observation this lcd tv, found that the problem could be in the T-CON board or LCD panel. Check LVDS and FPC cables, they are show as normal, then check the T-CON board voltages. All voltages in T-CON board are ok, so that i will suspect the TCON board mainchip (N39) or their memory chip (N31) defective. I got the junk T-CON board with same part number, but their DC-DC chip was burnt. So the mainchip and memory IC can be use.

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LED/LCD TV T-CON & Screen Panel Repair Guide Because of the N39 (CM2681) have many pins and the memory IC N31 (24LC128) only have 8 pins, so that I choose to replace the N31 first. After replace the N31, I try to power on the TV, and it was show display perfectly! Since this N31 is a memory IC, does that mean IC itself damage or just the firmware corrupt and caused this problem happen? To find out this answer, I use my programmer to copy the working memory IC firmware and write it into the original memory IC. Do you guess what has happen? Yes, the LCD TV working perfectly too! So the problem solved and it was causing by the firmware corrupted. The T-CON board memory chip or their firmware corrupt also can cause the screen problem. So that we need to save their firmware and must prepare some junk boards of T-con board, mainboard and inverter board for future use.

How to Repair the Display Washed Out Screen Problem Model: Samsung LA-37A550P1RXXM LCD TV LCD Panel: T370HW02 V.4 T-Con Board: T370HW02 When power on the tv, the screen is normal. But after about 10 seconds, it becomes blurring or nearly white screen/washed out. Like the picture below:

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LED/LCD TV T-CON & Screen Panel Repair Guide From the previous experience it is the T-con board problem. As usual, first check their T-con board top 5 voltages and other related voltages: Vcc input= 11.63V VGH= 27.01V VGHC= 25.89V VGL= -6V AVDD= 15.61V Vcom= 6.33V VGMA_REF= 15.56V So the above voltages are normal. So next will checking the Gamma section. *Below is the Gamma Voltage on T-con Board testing result: No. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

Marking Code VGMA22 VGMA21 VGMA20 VGMA19 VGMA18 VGMA17 VGMA16 VGMA15 VGMA14 VGMA13 VGMA12 VGMA11 VGMA10 VGMA9 VGMA8 VGMA7 VGMA6 VGMA5 VGMA4 VGMA3 VGMA2 VGMA1

Bad Values 0.362v 0.419v 0.544v 2.903v 3.574v 4.37v 4.84v 5.06v 6.31v 6.6v 6.64v 13.75v 13.78v 13.84v 14.23v 14.27v 14.36v 14.98v 15.5v 15.54v 15.54v 15.55v

Good Values 0.365v 0.42v 0.545v 2.905v 3.578v 4.37v 4.84v 5.07v 6.31v 6.6v 6.64v 7.91v 7.96v 8.31v 9.83v 10.1v 10.66v 11.62v 12.43v 15.28v 15.43v 15.5v

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From the above table, found the VGMA3~VGMA12 are abnormal. Because it is not a smooth ascending or descending voltage values for a Gamma voltages. Suspect their Gamma IC failure. After remove the heat pad and saw that’s a “popular” Gamma IC, AS-15F (U201)! So highly confident after replace this Gamma IC, it can cure the white screen problem from this TV.

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Why After Replaced the AS15-G IC to AS15-HG The TV Still Has Problem? The AS15 series IC is a 15 x Op Amp IC. It is 14 + 1 Op-Amp, 14 Op-Amp is for the GAMMA use and another one is for VCOM. Some TV repairer said after replace the AS15-HF to AS15-HG, the TV screen problem not solve or more serious than before. Sometime after replace the AS15 IC, the TV display is ok about 20 minutes, then whole screen change to nearly white screen about 3~5 seconds, and then screen back to normal about 5 minutes and then changed to white screen again. So the screen is non-stop to change like that, and the new replace AS15 IC can feeling extremely heat. Are the AS15G and AS15HG compatible? But when change to another batch of AS15 IC, the T-Con board problem solved!

Actually the AS15F, AS15G, AS15-HF & AS15-HG all are compatible and equivalent to use! But the problem is lots of the AS15 series IC in the market now is not in good condition or call is as recon IC. Especially the cheapest price of AS15 IC, this type of IC mostly has higher chances is not a good IC.

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The above picture of AS15-F IC, this batch of IC: 0452A, we found that after change to this IC, the IC is extremely heat on the T-con. Finally found the AS15-HG IC batch no: 1032B, after replace AS15-F with this AS15-HG, the TV display problem solved and the IC temperature is just feeling warm only. Even the AS15-HG batch no: 1210C also not good to use. Note: I have a tip for this AS15 series IC or even the AS19 series also same. When they replace the equivalent or compatible AS15 IC on the T-con board, if the finger can feel AS15 IC surface is very hot, but the display is ok, then I will recommend change another AS15 IC. Because it will cause this T-con board cannot last long to use. Or the AS15 IC is extremely heat on the IC surface and their TV display also abnormal, then direct removes it and replaces another one to try again. So lots of the TV repairer if they facing this problem before, hopefully they know what can do now and don’t confuse about it again.

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How to Easily Remove AS-15F IC without 3 Minutes Here has a question, how to remove this AS-15F spider IC easily? Because lots of the repairer facing a problem is hardly to remove this IC even using their soldering reworks station! This method you just need to use a utility knife and a normal soldering iron can easily remove this IC! Yes, within 3 minutes you can do it. But make sure you’re trying many time before. ☺

Use a small utility knife, put on the top of their IC pins, move the knife with one way only! Please don’t move the knife two ways, because it will hard to cut the pins and easy to damage the PCB board circuit line. One side of IC pins just moves 3~4 times and then next side. The strength and pressure to move the knife will depend by you to adjust it. After cut out four sides of IC pins, you can feel that IC can take out from the PCB. For your information, if the Gamma IC is AF-15HF or AS-15HG type, below or bottom of the IC has a ground or heat zinc solder on PCB there. So this type of IC is very hard to remove from PCB if using the rework station or hot air gun. But with this method it is easily to take out the IC. After cut out four sides of IC pins, use a flathead screwdriver to take (tilt) out the IC! So it is not a problem to remove this IC from T-con board.

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After removed the IC, use soldering iron, flux, goot wick and alcohol to clean it up.

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Before power on the Tv, please double check the Gamma IC AF-15F on the Tcon board. Is it any pin/s short together or any dirty solder on the pins there or not? If everything ok, power on the TV. Finally this TV is ok now.

Note: After replaced the AS-15F IC, if you found that LCD Display show a bit darkness than a normal display, that’s mean your AS-15F IC not soldering properly. You also can use the finger to press down a bit of this AS-15F IC, if the display quality can change a bit, that’s mean the AS-15F not soldering properly. So you need to re-solder this IC again. http://www.lcdrepairguide.com/tcon-panel/

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This LCD Panel Display Problem is Beyond Repair Do you know which type of display problem is can’t be repair? Here is the sample of the display problem you can refer: 1) Broken Screen or Screen Crack

Sure the LCD Panel if screen crack is beyond repair. If this is new TV, the TV manufacturer will not cover in their 2 or 3 years guarantee policy. 2) LCD Panel Liquid Crystal was Leakage Inside

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Troubleshooting & Repairing Hisense RSAG7.820.5129 T-CON Board This T-CON board schematic diagram was included in this ebook. The RSAG7.820.5129 T-CON board is widely used in these HISENSE TV Model: HE390GF-B51, HE460HFR-B51, HE500HF-B52 and HE500HFR-B52. All the above TV is using this T-CON board, but their program/firmware is different only.

T-CON Board Circuit Structure

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LED/LCD TV T-CON & Screen Panel Repair Guide Test Point 1.2V 1.8V 3.3V 1V 2.5V VGH VGL VSS AVDD1 VDDD1 VCOM

Voltage (V) 1.1~1.3 1.7~1.9 3.2~3.4 0.9~1.1 2.4 ~2.6 28 ~ 31 -9.0~ -10.0 -6.0~ -7.0 15.5~16.0 3.2~3.4 6.2~6.8

Test Point GMA1 GMA2 GMA3 GMA4 GMA5 GMA6 GMA7 GMA8 GMA9 GMA10 GMA11 GMA12 GMA13 GMA14

Voltage (V) 15.1~15.4 13.4~13.7 11.8~12.1 11.4~11.7 10.7~11.0 8.7~9.0 7.6~7.9 7.0~7.3 6.8~7.1 4.8~5.1 4.0~4.3 3.5~3.9 2.0~2.3 0.6~0.9

Test Point GMB1 GMB2 GMB3 GMB4 GMB5 GMB6 GMB7 GMB8 GMB9 GMB10 GMB11 GMB12 GMB13 GMB14

Voltage (V) 14.5~14.9 12.4~12.8 11.7~12.1 10.6~11.0 10.3~10.6 9.8~10.2 7.4~7.8 6.3~6.8 4.8~5.2 4.4~4.7 4.0~4.4 2.8~3.2 2.2~2.5 0.3~0.8

Panel Control Signals & Mini-LVDS Timing Chart Waveform Timing Control Waveform:

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LED/LCD TV T-CON & Screen Panel Repair Guide Control Signals DC Voltage Range Control Signal STV TP DATA POL CPV LC

PCB Marking GSP SOE POL GSC LC

DC Voltage (V) 0.002 ~ 0.3 0.2 ~ 0.5 1.0 ~ 1.5 1.2 ~ 1.9 0.15 ~ 0.5 2~3

Critical T-CON Board Output Voltage Values Test Point VCC_PANEL 1.8V 3.3V AVDDA1 VGH VDDD VGL

Standard Values (V) 12 1.8 3.3 15.8 29 3.3 -5.8

Voltage Tolerance ± 1.2V ± 0.1V ± 0.15V ± 0.25V ± 1.0V ± 0.15V ± 0.5V

RSAG7.820.5129 T-CON Board Module Features

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Module A. Gamma Circuit

Features Generate GM1~GM14 & VCOM voltage

Location NN7 (IML7991D)

Testing Point GMA1~GMA14\ VCOM

B. DC-DC

Generate 1.0V

NN14 (MP1484)

1.33V

C. DC-DC

Generate 3.3V

NN12 (MP1484)

3.3V

D. NT71790

T-CON IC

NN1

E. DDR

DDR buffer

NN2

F. Level Shifter Gate driving signals I. Flash

NN19 (RT8922) HC_L1~ HC_L6

Memory save T- N24 or NN5 CON firmware (25B40 or F40)

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LED/LCD TV T-CON & Screen Panel Repair Guide Introduce Module Features & Their Common Faults in T-CON 1) Module -A => Generate the Gamma & VCOM voltage

Common Fault: a) White Screen: Because the VCOM voltage abnormal or NN7 failure. b) Display compares to normal display more darkness: One or more of their Gamma voltages is 0V. First check the VDD_OP1 is it in 15.85 ± 0.2V normal voltage range. If yes, then check the VCOM & GM1~GM14. If their voltage is 0V, that’s mean the problem is NN7 failure. c) Left or Right side of the Screen their display darkness.

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LED/LCD TV T-CON & Screen Panel Repair Guide 2) Module-B => 12V convert to 1.0V This module provides the 1.0V core voltage to T-CON IC.

Common Fault: a) 1.0V no voltage: Normally is their NN14 dry solder joint or failure or RN234 & CN144 damage. b) 1.0V voltage out of their normal tolerance range: Normally is causing by the CN39 or RN6 failure.

3) Module-C => 12V convert to 3.3 Voltage Module This module provides the T-CON board 3.3V

Common Fault: a) No 3.3V: It could be their NN12 dry solder joint, RN235 & CN102 failure. http://www.lcdrepairguide.com/tcon-panel/

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LED/LCD TV T-CON & Screen Panel Repair Guide b) 3.3V Voltage out of the normal range: Commonly it’s their CN2 or RN2 failure. 4) Module D & E => Is T-CON IC and DDR buffer IC. T-CON IC

Common Fault: a) NN1 dry solder joint b) IC NN1 & NN2 chip defective

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LED/LCD TV T-CON & Screen Panel Repair Guide 5) Module-F => GOA Signal Control IC

How to know this IC is working or not? Use multimeter/voltmeter to measure the LC_L1 point, if the voltage range is in between 25V and -6V change, that’s mean this IC is working normally. If not, then this IC is abnormal. 6) Module-H => Panel Voltage Generated Circuit (VDDD/AVDDA1/VGL)

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LED/LCD TV T-CON & Screen Panel Repair Guide Common Fault: a) VDDD/VDDA/VGL no output voltage. The TV screen is no display but the backlight is lit: NN3 IC damage causes the VDDD/VDDA/VGL no output voltage. Check the NN3 pin-15 & 16 both pins is it short circuit. If yes, that’s mean the IC NN3 is damage and need to replace. b) When connect to Panel, the inductor noisy, screen display has horizontal line interference: Normally it is the CN212 failure.

7) Module-I => Flash Memory to save the T-CON IC Firmware

Common Fault: a) Flash memory NN5 failure Will affect screen no display (but the backlight is lit). b) NN5 IC lost firmware Will affect screen no display (but the backlight is lit).

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LED/LCD TV T-CON & Screen Panel Repair Guide

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Other Common Faults in this T-CON Board 1) Dry Soldering Joint or Pins Shorted Display Symptom Left side screen no display or abnormal display

Problem Location

Failure Reason XSN3 connector dry solder joint

Right side screen no display or abnormal display

XSNN4 connector pins shorted

Left side screen abnormal display

NN19 or NN21 dry solder joint

Display Grey Scale abnormal

NN1 damage

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LED/LCD TV T-CON & Screen Panel Repair Guide 2) Gate/Source COF Problem (Glass Cell Problem) This type of screen problem is not repairable, unless you’ve TAB bonding machine. If their ITO line/s defective inside the screen glass then this type of problem is beyond repair.

Description Vertical Line

Display Symptom

Horizontal Line

Vertical Block/Bar

Horizontal Block/Bar

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LED/LCD TV T-CON & Screen Panel Repair Guide 3) GOA Horizontal Lines on the screen

This GOA horizontal line evenly spaced (vertical 6 pixels). The Panel itself defective or the T-CON board Module-F (NN19 or NN21- RT8922) failure also can causing this type of screen problem. Check the IC NN19 or NN21 pins have dry soldering joint or not. If soldering ok and just replace this IC.

4) The bottom of Screen have some horizontal line/s jumping When the TV is in PC25 or HDMI mode, the screen bottom display has horizontal line/s (1 or 2 lines) jumping. But in other TV Mode, the screen is normal. This is because of the TV when in high density signals, their LVDS output signals is not standard type. And causing the T-CON IC output TE & STV signals time interval is 1.84ms (~1840us), but the original design is requirement is 147us! Use the oscilloscope to check the STV and TE signals and found like picture below:

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LED/LCD TV T-CON & Screen Panel Repair Guide

So the solution to solve this problem is updating the NN5 IC firmware to the latest version of LCM_T-TP_161240_B007.

5) Display Grey Scale Abnormal

Mostly, this type of screen problem is causing by the T-CON IC, Especially the production before 1240, their T-CON IC is the common fault. http://www.lcdrepairguide.com/tcon-panel/

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LED/LCD TV T-CON & Screen Panel Repair Guide 6) After Power On TV, Screen will show the Red, Green & Blue Display Non-stop Testing Mode

Normally this problem is causing by their TVS (FN2/FN3/FN4/FN5/FN6) damage. Use the Multimeter testing this TVS, is the ohm values to GND is lower than 1K ohm, that’s mean this TVS is damage by ESD already. Need to replace it with a good one. Or you can just remove this damage TVS and without connect anything, power on the TV. The TV should be ok now! 7) Display Abnormal in DTV Mode

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LED/LCD TV T-CON & Screen Panel Repair Guide This problem is causing by the T-CON IC NT71790. Especially the TCON Board production batch before 1240. 8) No Display/ Grey Display (Backlight Lit) a) The PMU circuit abnormal (Module H), NN3 (AAT1133) abnormal and causing the VDDD/AVDDA1/VGL no output or output abnormal voltages. Replace NN3 IC. b) Gamma circuit abnormal (Module-A). If Gamma IC output voltage abnormal, the output voltage range is about 6.7V~ 7.0V. Replace Gamma IC (iML7991D). c) NN1 dry soldering joint inside the bottom of this T-CON IC. Because of this IC is BGA package type, so we can use the oscilloscope to check their STV, LC, TP, POL & etc control signals waveform to confirm the T-CON IC is ok or not. If these signals got output, then this IC is Ok, if not, then it is T-CON IC failure.

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