My mac was running fine one day then suddenly powered off and tried to restart itself. Upon restart it was stuck with the loading status bar and the screen had 5 vertical pink lines across it.
Having done some research it is most likely a GPU solder issue which can be fixed by reapplying thermal paste or by 'frying' it in the oven. https://www.youtube.com/watch?v=nB172HJeM0w
Although some have said they have fixed it via safemode/updates etc
What causes 5 pink bars on 27" iMac (2011)?
Just wanted to ask on here before I go ahead with the baking method as a last resort.
-I cannot get my mac to boot at all and cannot get in to safe mode.
-I created a bootable USB stick and that would also not load using Apple+R.
-Cannot boot from my(external HDD which I normally use instead of the internal drive/os
-The pinks lines do go away when it attempts to enter recovery mode, which does give me some glimmer of hope that it's a software issue and not hardware. But it just gets stuck on a totally blank white screen before it gets to recovery mode.
I guess one thing I haven't tried is putting an actual DVD in the drive, but I threw those out years a go so would mean sourcing one.
Any advice would be greatly appreciated before I start trying to take it all apart!
It's an old model too, and I really only use it as a display for my newer MBP. So not worth paying to get it fixed
Thanks!
Best Answer
Safe mode and recovery mode tend to not load specific graphic drivers or acceleration, so the clear signal there tends to reinforce the hardware trace and LCD are still fine and the visual artifacts are GPU failures.
Your research is likely right that reflowing the solder might help remedy this or it will point to a more embedded failure. Either way, kudos for trying to reuse this. Next would be repair or recycle or sell for parts. People will want the power supply and lcd and other parts.