Chosen Solution
Hi! I can’t seem to find which ASD works for iMac 27" late 2014. I read somewhere that they discontinued the ASD in 2015, and since I have ASD for my MacBook 2014, I would think the iMac 2014 would have one too?
You can use the built-in onboard diagnostics, just restart your system and press the D key Reference: Mac startup key combinations What seems to be the problem?