2

Running High Sierra 10.13.6, I tried to install Security Update 2019-003, but it would not install because the computer gets stuck (blank screen, responsive pointer) when trying to restart. Now I see that the iMac will not shut down or restart under any circumstances. I tried internet recovery re-install of High Sierra, but it also got stuck during re-install and did not complete (probably due to re-start problem). Tried again in Safe Mode, no success. Tried resetting SMC and NVRAM. Apple diagnostic - no issues found. Disk First Aid - no problems.

Apple support suggested trying to install Mojave. I prefer not to at this time, but even if I did, I'm afraid that the restart problem will prevent Mojave install to complete.

Any suggestions on why restart and shutdown aren't working and how to fix?

You must log in to answer this question.

Browse other questions tagged .