Chosen Solution
Hi ~ After my mid-2012 MacBook Pro is woke up after being unused for about a half a day or so, it shows a black screen with the regular white apple, plus a row of about 20 rounded white bars below. This stays on for about 20 seconds, then all works fine after that. What does this indicate, please? Thanks much in advance! Update (11/10/2019) Sure, Dan. Thank you
A new condition for sure! I hadn’t seen this occur before. If resetting the PRAM fixed it then I think its safe to say you lucked out!
