Need Help! Tree Journeyman 310 - Z axis faults

Hello,
I have a Tree Journeyman 310 that the Z axis Baldor drive board failed showing Surge current status. I gave the board a quick look over and found the big bridge rectifier in the lower left side was shorted. From what I can tell it looks like it is being used as a back EMF device.
After replacing the rectifier the board powers up okay, homes okay, but only moves the axis in slow, if I try to move Z fast it fails with the following fault conditions.

- Emergence stop
- Z servo error loss of feedback or no motion detected on z axis
- Enter reset to continue

I need a drive board expert to help me understand what to try next. It may be as simple as a board adjustment. But I do not have any drive board setup docs. :-(

Any help with this would be greatly appreciated,
Bryan
Nampa, Id