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macrumors newbie
Original poster
Jun 9, 2012
Hi all,

I need some assistance for a reoccurring problem with a iMac 2010.

The problem has run through many phases over weeks (beginning with black screen with thin vertical white bars) on start-up, but through finally getting it to boot with a CD and reinstalling the existing OS it appeared to be fixed. Then it developed a new issue.

It then only very occasionally booted and most of the time shows the apple symbol, and process bar then the screen went white. I ran through all trouble shooting (safe mode, fsck, first aid, apple hardware test etc, PRAM reset) to no avail. Oddly it mostly booted when the OS boot CD was in the drive (despite me not holding C) whirring up when the boot normally failed. Booting to partition restore was not working, and internet restore was hanging on 24:00.

So I made a Sierra boot drive, wiped the HDD and installed a fresh Sierra OS. It appeared to be ok. But the next day the same white screen on boot is back. It's bizarre how intermittent it is.

I booted in verbose today and it went white after the last screenshot. This final message appears to be a Nvidia compatibility issue, however this was happening with El Capitan installed before I installed Sierra. The iMac was shipped with Lion and has an AMD.

I'm not an IT guy but will try to provide what's needed to weed out the issue so all help is hugely appreciated. Would you recommend a reinstall of the original OS?


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