This tv is about 10 years old. The screen will go 90% black. You can still hear the sound and see the perimeter but 80-90% of the screen is competely blacked out. It only happens on the TV. It does not matter what channel. This has been going off and on for several years. There is no warning it just happens. We just turn if off and it may be okay the next day when we turn it back on. Has anyone seen this and know how to correct it? Thanks, Jerry