Chosen Solution
Hi guys, my iMac recently froze and when I tried restarting, some vertical lines showed up but the Apple logo still loaded. Once it finished, some squares popped up all over the screen. PLEASE SEE VIDEO I would really appreciate some help.
Update (07/24/2019) When the little squares show up, the external screen then turns on and is completely white. So I guess internal display then?
What does an external monitor look like? Does it show the same image? If it does the GPU has failed. If it looks OK then the internal display has failed. Update (07/24/2019) Time for a new GPU card iMac Intel 27" EMC 2374, AMD Radeon HD 4850 Video Card Removal & Repair
