Chosen Solution
Below are some photos I took this morning of an issue which seems to be happening more and more often. I haven’t taken steps to fix it yet, because typically it will fix itself after being powered on for about 10 minutes. Typically after that, it will stay working for the rest of the day. Unfortunately, this has been happening almost every day now, and (at least so far) hasn’t righted itself today. I suspect there is something wrong with the display’s connection since the display clearly can function properly outside of these episodes and resetting NVRAM (at apple support’s suggestion) did nothing. Has anyone seen this issue before?
This looks like the display board has been damaged or is failing. To confirm, hook it up to an external display. I repaired one yesterday by replacing with a new screen: MacBook Pro 13" Unibody (Mid 2012) Display Assembly LG Philips lp133wx3 (TL) (a6) lp133wx3-tla6 Apple LCD Screen 13.3" Screen LED https://www.ebay.com/itm/LG-Philips-lp13… but this is a very difficult repair. But do-able. So you can spend $45-65 and spend 2-3 hours or find a used one for under $200. MacBook Pro 13" Unibody Mid 2012 Display Replacement
