Emerson flat screen tv with red stripe

The pixels on your screen are controlled by a matrix composed of switches that turn off and on to produce light.

They are located vertically and horizontally, row-wise and must function together to produce everything from black (everything turned on so no light, or very little, can escape) to layers that represent the three colors that are used alone or in combination to produce the millions of possible shades of each.

One of the switches that controls one of the vertical columns has failed and has turned on the entire column that allows red to display.

The problem switch (a semiconductor combined with many) is permanently turned on, probably part of the screen assembly itself, and was placed with others by robots.
The pin spacing on these 'chips' is very small and often makes the assembly unrepairable.

While LCD panels have fallen hugely in price, you may be looking at a parts cost (labor is probably not too bad) that may make you decide to replace the set.

Unfortunately, the once-proud Emerson name has sadly been degraded and there is a lot of their electronics available from companies that specialize in 'refurbished' products, an indication that they have a large failure rate.