My Vizio Plazma 42in hdtv has a 2inch red verticle stripe on the left side and now the right side of the screen. It is a 4 year old 2400 dollar set I go at Costco.

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/
Line, faults & possible causes to LCD screen are given with illustrations. You can get an idea about the fault to an extent.

It sounds that the back-light CCFL lamp is faulty. It is time to replace it. When replacing, do it to all CCFLs, because, the life time to these lams are expiring now, as the set is nearly 4 years old. Check this link http://electronicshelponline.blogspot.com/ to get more details about how to replace the CCFLs. Pull up older posts there. Some among it have details.

If there is no auto dimmer on the TV, than the TV needs professional repair work.

This is common and very likely the LCD panel has lost its connection at those points around the panel. Most repair shops don't even try to fix it as it is a huge pain to try. You should be able to get a warranty replacement if it is new.

it's burning out. that's a sign of tv failing. there is no repair for that if you used it for 5 years, i doubt you would have warranty for that by now, best option is to replace it.

I would try a couple of things. First and cheapest way is to try and update your driver. If that does not work, then try to remove and reseat your memory card(s), and if all else fails you will need to buy a new graphics card approx 75 to 150 depending on how good you want to go.

if you have a picture then the light engine is probably ok.
the FMT and the DM boards cause this.
visit www.tv-techs.com

I'm not an expert, but I have determined that the vertical bars that are often red, sometimes blue ... and sometimes both ... are related to a bad control board. I've also read that a common fix is to buy a repair kit with includes the ysus, zsus and control boards ... all replaced together. My experience was that after a month or two with the 1.5" wide stripes, that you eventually loose the entire picture and have sound only. MIne comes back, but won't stay working for very long and the stripes are always there (buy used to fade and flicker sometimes). I'm planning on replacing the control board.

Try changing the H/V position in the TV Set Up menu. You can adjust the horizontal and vertical position of the screen and move it enough that the green line disappears from the screen.

I have the same problem. I had a tech guy come to the house and there is a part that needs to be ordered for it. If you have a warranty it is free but if not the tech guy said the part costs from $450 to $500.