[Keith]’s cousin gave him a LCD with a noisy backlight. He decided to replace it with a series of high output LEDs. He sourced some locally in the form of cheap LED headlamps from an auto-parts store.

Some 4K TVs have QLED or OLED displays, but most are LCD, and many of those have LED backlights. When you're shopping for a new TV, these are the sets you'll come across most often. We're going to ...