LG SMART TV 55 INCH 55LN5700 Which board to relpace

It sounds like you may have a problem with the video signal on your Vizio 55 inch flat screen TV. The fact that the TV turns on and has sound, but no video and vertical lines on the screen, suggests that there may be an issue with the video processing or display.
It could be a problem with the T-CON board, which is responsible for the video signal processing. It could also be a problem with the LCD panel itself.
It's also possible that there's an issue with the cable connecting the T-CON board to the LCD panel, or a problem with the software on the main board.
I recommend consulting the manual of the TV or contacting the manufacturer for further assistance. A professional technician should be able to diagnose and fix the problem.
It's also possible that the issue is with the mainboard or the T-CON board is not compatible with the TV. Thus, it's best to check the compatibility of the parts with the TV before installing it.

Replace the jack wires going to the LED strips. Or look for the one bad jack wire going to the LED's and fix it. Use a volt meter on ohms to find the bad wire.

Why would you replace the power board for a burnt out backlight problem??

hi check the led driver board for dry joints, what is the voltage you tested, my guess is the led in the panel has shorted out, thanks

shaun

hi the led or leds has shorted in the panel, thanks

shaun

Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis. http://electronicshelponline.blogspot.com/ To some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement. To some models sets, the back-light inverter and SMPS section circuit will be integrated at its main board itself. If so; the main board should be replaced. To some models of sets, all these section circuit will be integrated at its main board. If this is the case, you have to replace the main board.

LG 42LS5700 - LG.com

www.lg.com > Home > Support > Product Support

LG ElectronicsTV/Audio/Video; TVs; 42LS5700 ... TV Support Landing Page - HDTV/Netcast/webOS 1.0/webOS 2.0 ... Adjusting Picture Settings - webOS 2.0 Video ... quality and convenience of complimentary shipping when buying directly from LG.com. ... Curved TVs · 22 Inch to 29 Inch Class TVs · 32 Inch to 39 Inch Class TVs · 40 Inch ...

Amazon.com: Customer Reviews: LG 42LS5700 42-Inch ...

www.amazon.com/LG-42LS5700-42-Inch.../B006ZH...

Amazon.com, Inc.LG 42LS5700 42-Inch 1080p 120Hz LED-LCD HDTV with Smart TV (2012 Model). byLG. Size: 42-Inch ..... images are nice and crisp when viewing HD content.

Widescreen TV Black Screen - Repair LCD LED PLASMA ...

? 3:41
https://www.youtube.com/watch?v=RbZncfiOXQA
Jul 13, 2011 - Uploaded by FixItUrselfDummy
Fix your tv with black screen blinking light, popping sound noise. ... Watch QueueQueue ... TV Black Screen - Repair LCD LED PLASMA - Problems SONY LG .... I have a 60 inch samsung DPL tv how can I stop the humming or ... What do I do if my tvturns on but its just a black screen so sound no picture?.

Not sure how you could have power coming out the cable in terminal, Ive repaired thousands of sets and have never seen that...how much voltage do you have there?

Back - light problem. Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis.
http://electronicshelponline.blogspot.com/
Some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement.