I may have hacked a solution to the iMac screen, specifically I think the iMac 2011, going dark or just black! Problem: I have an iMac 2011 someone donated to me because the screen went dark after brightness of 3 or 4. I’ve used it a long time, but recently its screen just failed to turn on. Tried PRAM, SMC, even fresh copy of High Sierra using an external drive. Nothing. Potential Hack for others to try, or learn from. So I got out my older iMac 2009. I use the iMacs for 2nd monitors, using their Target Display capability. I plugged in a DisplayPort cable from the iMac 2009 to my MacBook Pro 2014. Everything is working fine, just using the older iMac. I keep wondering about solving the black screen on the iMac 2011. So I then shut down the iMac 2009, unplug cables. Get the iMac 2011 up on the desk, plug in the cables, including the DisplayPort to the Macbook, and WOW, up powering up the iMac, the screen came back alive!!! And once the iMac Please update this community if you test this and find it works,...

Thank you for updating this. Of course would love to hear if the issue goes away or lessens.

THIS SOLVED MY ISSUE(s)! I have a Macbook Pro 2014 Retina and installed an OWC Aura 1Tb drive years ago. I fought behaviors that sound very similar to the comments above. I called OWC and they were very helpful. Here is the text from their tech support… this solved the issue. Here is the text of OWC’s email… Jan 2020 "While we cannot always reproduce it, we have identified the issues being related to Apple's NVMe system resources. We have submitted a bug report to our contact at Apple, and are concurrently evaluating the possibility of a driver-level solution for our customers. In the meantime, please use the simple workaround below to prevent your system from entering Standby mode when it is sleeping. Workaround Open the Terminal app Type the following: sudo pmset -a standby 0 Press Return Quit the Terminal This prevents the computer from entering Standby mode while the computer is in normal Sleep mode. From this point, allowing the computer to return to sleep and then waking the computer, should prevent...