Question: Mac,stuck in reboot loop, after high-sierra update
(Mid 2011 iMac 27 inch upgraded VideoCard option)
I'm being being vexed by the following problem. I updated to the new High Sierra update 3 days ago...The iMac restarted after the update and seemed a bit off after the reboot. The next day the computer was started and the iMac went into a continuous reboot cycle It almost makes it to the end but then the screen goes white and the computer restarts with the apple logo and loading bar... No interventions work from the wireless keyboard and the keyboard caps is not responding.
I took it to the genius bar and they could not get the iMac to reload or re install the OS. The tech ran a battery of tests that the iMac passed but it failed a video test. The estimate to replace the video card with a 90 day warranty was 800-900$.
I'm not convinced that its a video card failure since I don't have any fluttering or fluctuating pixels/screen images.
How can I make sure that It is the video card and not a hard drive issue?
With kind Regards
iMac (27-inch Mid 2011)