I almost never reboot this Mac. Lately I noticed after a system freeze that the Mac would not boot, instead the Mac boot process hangs at a black screen.
- Unplugging the USB devices immediately continues the boot process to the gray screen with the Apple logo.
- Because 2 USB hubs are attached I tried to isolate, by moving all USB devices to one USB hub and then to the other, no improvement.
- Tried to isolate the individual USB devices, boot still fails.
How to fix the boot process of my Mac?