The first question is whether the power supply is still working. Try measuring it directly, to see what it’s actually outputting.
As to the solution, that depends a great deal on what is wrong. If the power supply is damaged, you’ll need to replace it. The microcontrollers are quite tough, and rarely get damaged, even by brief overvoltage or reverse voltage. They can, rarely, get into a situation where they need to be reflashed, and yes, our source code is available online.
We do sell power supplies that work well to power multiple boards; our 5 V 1 A board powers up to 5 Octolively modules and our 5 V 3 A board powers up to 15 Octolively modules.