Chosen Solution

If I replace the logic board example with this iPhone 6 Plus Logic Board - Verizon / 16 GB would that get the phone of the black list? Guy

Sort of… If you replace the logic board with one that is in proper condition, then yes. It will work just fine. However, going from what you’ve said, or phrased this, you can’t use an iPhone 6 logic board, in an iPhone 6S. And, you definitely can’t use an iPhone 6+ in an iPhone 6S