[Gogar]

Do you know which breaker is 'supposed' to be feeding these dead boxes?

You could always get a roll of wire and (with the power off) do continuity tests from one box to the other to see if they are all on the same circuit, or a few circuits, whatever


If you know which breaker it is you could always (with the power off), pull it and swap with an identical breaker from the panel and see if anything changes.