Chosen Solution
Just replaced cracked display. New display boots up with bright apple logo but then goes dim - probably about 40-50% of normal brightness. Have already reset PRAM and SMC. Reseated display cable.. Help?
See if the F2 key will brighten it up. The LCD panel may also needs programming if EDID code is not accepted by MacOS auto brightness won’t work and brightness adjustment won’t work. Here’s how to do it: https://gist.github.com/ejdyksen/8302862
