For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
I have a 820-3437-B works fine except when adjusting the backlight brightness it jumps from one brightness setting to the next. Its jerky/choppy vs being a smooth transition. I replaced the backlight chip and no change.
Pram reset didnt do anything. its not too noticable but when holding the brighness up or down button its not as smooth as it should be not too much of a problem but just wondering. Its not letting me upload a gif its saying too large its around 3.7MB
Quick update: I ordered 40x LP8550 from the mouser link above, and they still have the choppy-adjustment. So, I'd avoid buying from there if you were considering.
Haven't tried the python script fix yet, not sure how, but the mouser part isn't a fix.