No such thing as a free spa.
How?
Sounds like a bad pump or electrical issue.
Uh-oh.
I assume you mean the air controls?
Again, assume you mean air controls?
Could be the wrong voltage or hp pump. Have you checked?
Please explain what this means.
For starters, check the hp and voltage of the pump and compare with the old. Then check that the board is switching it on and off as it should. A stuck low speed relay will run constantly in low and trip breakers, blow fuses, and burn up motors in high.
Post pics of circuit board, wiring diagram, and equipment area.