Last week my 2010 Mac Pro running 10.12.3 suddenly started getting stuck booting at the gray Apple logo and progress bar screen. The strange thing is that booting in verbose mode completes as expected. That can be a work around, but I don't trust the stability of the computer if something is getting in the way under normal operation.
- Running first aid on the boot disk and rebooting. No change
- Resetting PRAM and SMC. No change
- Wiping the boot drive (data is on a separate drive) and reinstalling macOS. Gets stuck after the installer reboots
- Reseating the drives and CPU tray (along with a cleanup of internal dust). No change
- Swapping out the boot drive with a spare. No change