This TV turned on with no backlight. I found four intermittent LEDs on one strip and replaced them with 3V Samsung compatible ones. To turn down the backlight, you need to go into the service menu. For this model, with the tv on, push source-2-5-8-0 on the remote and the backlight level is under Panel Settings. I set it to around 55. This value needs to be set on EVERY input and may apply to only the current picture setting (Standard, Energy Saving, Dynamic, User).