62MX195 right half of screen brighter than left

[BIC]

I have a 6 year old Toshiba 62MX195. Lamp was replaced under warranty after first few months. So lamp is 6 years old but average usage only about 2 hours per day.

A few months ago, with a completely black screen, I noticed the right half of the screen as brighter (or worse black level) than the left half of the screen. Not exactly 50-50, maybe 55% left-45% right. More recently, I noticed it in dark scenes. Don't know if it's getting worse, or I'm just noticing it more. Overall, black level seems worse than it used to be, but could be subjective perception. Thank you for any help you may provide.

[BIC]

Thanks. I was guessing that after reading some other posts here. Time to look for a new TV.