I’m trying to troubleshoot my screen that suddenly went dark… I closed the lid one day, not long after updating my mid-2015 MBP 15” to Mojave, and then tried to use it again and the screen wouldn’t come on. I tried all the reset procedures I could find online and none of them worked, but I am able to get into my computer with an external monitor. This should mean the dark screen is a hardware and not a software issue, correct? If I open the back then what should I be looking at?...it’s strange that it just went dark and I'd have a hardware problem without any physical bump or anything…