Hi - I have a Q90R, and in many cases the picture is superb. I can live with the occasions where the Local Dimming is a little too obvious, but the Global Dimming is really annoying - a scene displays and suddenly the whole screen dims.
I followed the instructions on this video (https://youtu.be/ov9niiau5x4), entered the Service menu and set PWM_MOVIE_INI, PWM MID and PWM Min all to 100. Many comments on that YouTube express delight with the results, but for me, the Global Dimming still happens. I 'think' it's better than it was, but it still happens.
Any advice would be much appreciated - thanks.
Eventually I caved - I moved the Q90R to the kitchen where the TV is not for movies, and bought a QN95A for the Lou he, and that TV is very consistent once you find the settings you like - no crazy dimming.