My 3-year old Samsung UE32H6400 has recently started showing a translucent sharp-edged band at the left hand edge of the TV screen, maybe 6 inches wide. It's more visible in lighter scenes. I've tried the self-diagnosis, and it failed all 3 tests (although it's much harder to see in the greyscale vertical banding tests, so it's possible it might have passed one or both of those). It's on the latest software version. I tried putting it in Movie mode, as per suggestions from some similar threads, and I've also done a factory reset; if anything, it's a bit worse now!