LED television is flickering what is wrong?

Unfortunately no...only fix will be to replace the panel and they cost more than the set cost new

The main power supply regulator section circuit fault. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Pull up older posts. http://electronicshelponline.blogspot.com/ It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size.
Search the site by type in the "brand name" to your device; in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

Start with finding the model of your TV
https://www.shopjimmy.com/lg
Then


LCD LED TV Repair No Image Blank Black Screen Flashlight Test How to Fix...

Fault at its main digital board. Short circuited component/s at it. Contact any service technician; or the authorized service center. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/
In most cases, the main board might have to be replaced. If so, a software [firmware] update too might be necessary.

how to fix led tv vertical lines on screen 55" model lg 55lx6500

? 9:47
www.youtube.com/watch?v=zE0eqB4Ppjw
Nov 11, 2012 - Uploaded by LUFERQUINT HOW TO FIX LED TV VERTICAL LINES ON SCREEN 55" MODEL LG ... TV Repair Help for Vertical & Horizontal Lines on Your TV Screen ..

If all your other HDMI inputs are out, then I recommend replacing the MAIN PCB
try the following web site: https://www.encompassparts.com/model/ZEN55UB9500UA/_/_/LG/55UB9500UA/55_INCH_UHD_4K_SMART_3D_LED_TV_W_WEBOS
page 4 lists a part number for the MAIN PCB,
HOWEVER, PLEASE MAKE SURE YOU USE YOUR COMPLETE MODEL NUMBER TO ASSURE THE CORRECT PART.

http://www.lg.com/us/search/srch_manuals-tab?customerModelCode=55UB8500&mobileFlag=N#

Restoring the Default Settings
"> ">General > Reset to Initial Settings
Delete all the TV settings data and reset the TV. All the options in the Settings Menu will be reset to the default settings.
After reset, the TV will automatically turn off and on.
Type the password to Reset to Initial Settings
Do not turn off the power during initialization.

Corrupted firmware. An update is necessary. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Firmware (Software) update procedure of many popular brand TVs and other devices are given in detail.
Search the site by type in the "brand name" to your device; (Exclude the model number), in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

if you are getting the logo and snow , I think you are on the wrong channel for programming

First thing to try would be to update the firmware. This link should take you to the LG support site where you can find the download and instructions you need to update your television. Look under drivers and software. Good luck.
http://www.lg.com/us/support/product/support-product-profile.jsp?customerModelCode=55LE5500