If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/Faults & possible causes to LCD screen are given with illustrations. You can get an idea about the fault to an extent.View the site by desktop or web view on mobile devices to see the "search box". Type in the brand name of your set in search box; to get gathered the related posts...
To fix this, you need to do something called degaussing. You should keep magnets away from the screen in the future, because they cause this problem.
The first thing to try is to turn it on and off, making sure that all magnets and speakers (which have magnets in them) are kept far away from it. This will activate the monitor's auto-degausser if it has one.
If this does not help, this guide: http://www.wikihow.com/Degauss-a-Computer-Monitor gives a couple solutions, including using a soldering gun (not a soldering iron), illustrated in the video below:
With a powerdrill:
Or investing about 60 bucks in a degaussing coil like this which is a guaranteed fix:
One other trick that might work is to take an old CRT monitor ("fat-screen" rather than "flat-screen"), hold it up to the tv screen to screen, and turn it on and off to have the monitor use its own degausser. The monitor may have a button to activate degaussing, or it may be in the menu you can bring up with the buttons on the bottom of the screen.
If you don't want to deal with any of this, a tv repair shop will degauss your tv for you quickly.
Fault with TV remote sensor section circuit is very rare.
Check the remote control for its infrared emission. Check it with fresh batteries. Check it by pressing all the keys. You can detect the presence of infra-red emission from the remote control, using a cell-phone camera. If you wish to get more details about how to check a remote control, please visit this site. One among the posts has details about it. In some cases, the remote control might need to clean.
https://electronicshelponline.blogspot.com/https://homenol.blogspot.com/https://remotesearch.blogspot.com/
Search the site by type in this key phrase "how to test a remote control "in the "search box at the top right of the display window of the Homepage" to get the related post quickly.
https://youtu.be/wUpnETSm6_khttps://www.youtube.com/watch?v=jsSCNCW3IbQ [open and clean]
https://www.youtube.com/watch?v=Qp-l1uh-5gE [open and clean]
If less than a year old, this TV is likely under warranty but should have been taken back immediately to address the issue. I suggest contacting the vendor or manufacturer.
It might be that the sound amplifer is defective if you know anything about electronic you can fix it . If not better take it to someone who can repair it.
The amplifer is the part of electronic that amplifies current so the speekers can be driven. Check it if there is a bad solder or anyhing suspicious.
If its a LCD set not plasma I would look at the connectors going in and out of the Tcon board, remove them and reseat them, if that doesn't help replace the board.
There is one other thing you can try and that is remove the board and put it in your oven at I think its 370 degrees for 10 minutes, Ive never tried doing this but there are some vids on people having good luck doing this, what happens is there are some cold solder joints on the components and putting it in the over will heat them up and the board will work again, search this on youtube and there are vids on how to do it.
