I am in the jungle visiting family and I always try to fix all their electronics while I am here

A few years ago I gave a family a TCL LED55P65US tv, and now i am back and it is having some issues.

There are constant, shifting horrizontal lines across the screen and the screen flashes every 1.5 seconds or so, as seen in the attached gif.

Ive been through a few troubleshooting steps and no luck so far.

Does this seem like a possible T-Con board issue or does this seem unrepairable? The tv has been in a high heat and high humidity area, and the...