Chosen Solution
I have a late 2009 27 inch iMac . It’s the i7 version if that matters . The power supply went out In 2015 and my husband fixed it . After a power outage it started making a buzzing sound and then the cursor started displaying 8 rows of dots . It won’t boot unless I’m in safe mode . How can I fix it ?
This is a GPU failure, a well known issue on this model. Here’s a video on replacing it: https://www.youtube.com/watch?v=Lpa5B6bC…
