I have an 87 model and recently notice that my picture settings no longer hold their values. I change a picture settings like brightness in "Custom" mode for example, then after 20 mins or so, there's a black screen, and my setting are returned to their previous settings. Doesn't matter if is Custom, Dynamic, Movie, etc. they all change back. Is this beginning of the end? I love this TV and don't want to get rid of it but I do not want to spend $1,000 to fix.
Is it reverting back to dynamic mode? If so, it's just in shop mode. User settings reset to default “dynamic” settings after 20 minutes. This mode is turned on for display models, allowing potential customers to adjust user menu, but the TV will return to the “showroom settings” after 20 minutes.
To turn off shop mode, with the TV in the “on” state, hold down the “menu” button on the front panel for approximately 5 seconds until “dynamic” is displayed in a blue box at the bottom of the screen. Then put the TV in whatever mode you prefer and adjust user settings as usual.