Sounds like in TV tube or monitor when you lose a pixel. In these displays, i don't know what kind of tech they use. Would seem you either lost a 'pixel band' or there is a defect in the circuit that renders the image (say a capacitor went out and had an effect on imaging). I think the screen defect is more likely. You can go effectively forever with a pixel out....not sure if there is any way of knowing if it will get worse/lose more.

Believe service is listed on the Garret's site. Virginia and near Sweet Home, OR (Lebanon i think).

Hopefully that gives you more to google!

Zincoln