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My Mac Pro boots up fine, takes my password, then 2/3rds of the way loading the progress bar goes to a black screen. I need to disconnect and reconnect my Thunderbolt 3 cable connected to my LG UltraFine Display to regain picture. Anyone else have this issue or a solution?
Mac Pro, macOS 10.15
In regular Mode, just after the password is entered, your Mac transitions to using accelerated, interrupt-driven operation. A failure in the graphics system at that point would leave the screen blank.
Contrast that with what should happen in Safe Mode, where the graphics acceleration Driver is never loaded. There, after you enter your password, the screen should stay lit, but screen updates (without acceleration) will be wonky and slow, but ultimately correct.
If this follows my prediction, you may have faulty graphics card.
Safe Mode takes defaults for as many things as it can, and may use a lower screen resolution. Any changes you make and save in Safe Mode (such as changing screen resolution) are intended to "stick" in regular mode.
In regular Mode, just after the password is entered, your Mac transitions to using accelerated, interrupt-driven operation. A failure in the graphics system at that point would leave the screen blank.
Contrast that with what should happen in Safe Mode, where the graphics acceleration Driver is never loaded. There, after you enter your password, the screen should stay lit, but screen updates (without acceleration) will be wonky and slow, but ultimately correct.
If this follows my prediction, you may have faulty graphics card.
Safe Mode takes defaults for as many things as it can, and may use a lower screen resolution. Any changes you make and save in Safe Mode (such as changing screen resolution) are intended to "stick" in regular mode.
Thanks. Been working with Apple Support on this one. It fails in all Safe Mode, Recovery Mode, and Internet Recover Mode with this LG 4K Ultrafine Display. I tried a new Thunderbolt USB-C cable, same issue. Do you think it can be a defective monitor (saving me a trip to test the video card?). FWIW, it does seem to work OK with an much lower resolution portable SainSonic USB-C monitor https://www.amazon.com/SainSonic-Multi-Touch-Portable-Speakers-Nintendo/dp/B07Q6XPPV7
New Mac Pro 2019 black screen after boot
