Two Serious Problems With New 10-core iMac Pro
On December 26, 2017 I took delivery of a 10-core iMac Pro. From the time of its arrival I have had two serious problems that may or may not be related. (1) External USB3 hard drives (I have tried a variety from different manufacturers) attached to the ports on the back of the iMac Pro are ejected 95% of the time when I wake the iMac Pro from sleep. If I restart, the external USB3 hard drives reappear and function perfectly until the next time I put the iMac Pro to sleep . They do not dismount during use. The only setting I have checked in System Preferences>Energy Saver is “prevent computer from sleeping automatically when display is off”. (2) If I have any USB3 hard drives attached to the ports on the rear of the iMac Pro, I am unable to boot into Windows 10 (freshly installed using Bootcamp Assistant icensed version ). If all the USB3 external hard drives are unplugged from the iMac Pro, I am able to boot perfectly into Windows 10 provided I use the procedure of System Preferences>Startup Disk, click on Bootcamp, and select restart. If I try to use the method of holding the Option key and restarting to bring up the Startup Manager and then select Windows, I am unable to boot into Windows either with or without USB3 hard drives attached. Windows simply hangs at the Windows logo with endlessly spinning circle of white dots.
To solve these problems I have tried: (1) resetting the SMC Controller; (2) Resetting the NVRAM; (3) completely reinstalling the Mac OS High Sierra software using Command>Recovery; (3) Using a variety of USB3 HD’s from different manufactures. None of this has resolved the two issues. I am now able to use my new iMac Pro with only the supplied keyboard attached to a USB port on the back of the iMac Pro and two external Thunderbolt HD’s (which do not produce any problems).
Any solution that you can supply to these issues would be greatly appreciated.