How to disable auto-brightness on a Samsung TV

I bought a Samsung TV around two years ago (model UN55TU7000BXZA). It's a pretty decent cheap TV except it has a "feature" that bugs the crap out of me. When the picture it's displaying is mostly black, it will dim the entire backlight, making whatever's not black harder to see. No matter what settings you change in the picture or power-saving settings (disabling contrast enhancement, disabling auto-backlight adjustment, etc), this behavior remains. I'm assuming they're doing it because it makes the TV's power consumption look better. I had to dig for a while before I found this method buried in Samsung's forum, so hopefully this page makes it easier to find. This involves messing around in the service menu, which has stuff that can break your TV and may or may not invalidate your warranty. Don't hold me responsible if your TV stops working because you did something in the service menu!

Steps

  1. Enter the service menu. There's like 10 different ways to do this depending on your TV, so search around. What worked for me was turning the TV off, then pressing (one at a time) Mute, 1, 8, 2, and finally Power. Your TV will turn on. After around 10-15 seconds, the service menu will appear on the left side of the screen.
  2. Go to SVC -> Other Setting -> CAL Data Restore. You'll see a "USB not connected" error. Click OK.
  3. Press Return on your remote until you're back at the main service menu. You'll now see a new Advanced option at the bottom. Highlight it and hold the volume up key on your remote for 5-6 seconds. You'll see more options appear below Advanced. Note: Samsung has changed how this works in newer firmwares. If the "volume up" method doesn't work, try highlighting the option and pressing 0000. If that still doesn't work, try 0038.
  4. Select Picture_2D -> Subsetting.
  5. Change both the PWM_INI_2D and PWM_MOVIE_INI settings to 100. If you want to reduce the dimming effect rather than turning it off entirely, you can make these smaller (the Samsung forum post suggested 75-80).
  6. Back out to the main service menu by pressing Return repeatedly, then turn your TV off and back on to get out of the service menu.
  7. The service menu resets the user-accessible picture settings to the out-of the box "showroom" aesthetic (super bright, contrast maxxed out). You'll have to adjust them back to how they were previously.

If this didn't fix the problem, please do not contact me because I will unable to offer any additional advice.

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