Hello, and sorry you're having problems. We are now connected on this website- which saves you money over having a Tech come to your home, and in many cases we can fix the problem you're having. In other cases, these things do require additional parts to fix. But I can help you with that as well.
Offhand a line on the screen is a hardware fault- not something that can be fixed with any settings or adjustments.
Now, this can be caused by the "Source" (cable/SAT box, DVD player, etc.) or within the TV itself.
Grab the original Sony remote and find the HOME/MENU button and press that button. Let me know if the MENU displays over the line, or if the line is over the MENU. If it's over the MENU, then this is a hardware failure within the LCD processing of the TV that requires repairs.
Let me know what you find- line over the MENU, how thick the line is, is it black, or colored, etc.?
Feel free to reply back if you need more help, or want to reply back with more details. It does not cost you anything more to reply back once you've rated. Please do rate me positively (at least 3 STARS) and I will continue with you until this is sorted. The positive rating ensures I am credited for my work.