I have to assume the powerheads that spin backwards are the non controllable models which should not be used on any wavemaker. This would just be a matter of a new drive unit. I need more info about what model pumps they are and how old they are. Also, where are you located?
The 7095 in all likelihood works, it is the connected pumps that would emit a beep from there driver boxes. If one pump is bad it can cause the unit to stop working. I would try all pumps without the controller to isolate which one(s) are bad.
The 6261 is a wavebox pump, I am assuming you have complete waveboxes? These unitscan be controlled by 6091 or 7096, 6091 you can order on tunze.com, 7096 is available from most dealers and can run controllable pumps as well as waveboxes.