Resolved: "Instrument Access Failed"

[shoppinginmyslippers]

I experienced many problems with an old GretagMacbeth i1 Pro on my Mac Pro 2010 with Mojave.
Each time I tried to calibrate my monitor, the test ended prematurely with “Instrument Access Failed” or “Communications Failure.”
After much research, I discovered my power supply is operating at near capacity and doesn’t have  enough power for the i1 device too.
So I plugged it into an externally  powered USB 3 dock and it now it seems to work as intended!
(I also removed a few orphaned xrite files hidden in the operating system files. )
I don’t know the power requirements for the i1, and I used the Fideco hard drive docking station which comes with a large power supply.
I would think other powered USB stations should work as well.
I hope this helps someone!
Biff

[Author]

Posts