Convince Isaac to tell you what the power armor security codes are was going to be a quest in Van Buren, the canceled Fallout 3 by Black Isle Studios.
Before Isaac left Maxson bunker, he locked down all the unused suits of power armor with a security code. Naturally, the remaining Brothers aren't too happy about that. The PC's mission is to convince Isaac to reveal what the codes are.
The Mesa Verde design document gives one way to complete this quest.