Nic - As a follow-up to my problem: I determined the problem with my GPU reporting error code 43 to be caused by the 207 BIOS revision for the Asus N550JV. Downgrading my BIOS version resolved the issue. I should point out that Asus refused to help me with that process and insisted I send it into them for repair. I found instructions on how to do the downgrade in their forums by another poster. I notified Asus support of the problem that BIOS revision caused and my success, but I doubt there will be any follow up on it.
Probably a good idea to file this away for Asus owners. I saw at least one other user on this forum who had the exact same problem with the same model laptop I have.