I'm a bit too late to help Allen, but this may help someone else with problems.
These motors and controller boards are notoriously unreliable (I have several to prove the point!), and spare are not cheap.
The DC brushed motors can be tested by connecting to a 12V DC supply (car battery) - it should tune smoothly, but not too fast (its only 12V, not around the 150V from the controller). If it sparks, 'stutters' or vibrates - you need a new one. There are several different versions of the controller over the years. They all seem to suffer from the output stage failing (usually MOSFETS). They can fail open-circuit or short-circuit. If open, the motor won't turn, if short, the motor runs at high speed, and is uncontrollable. If you know what you are doing, the output devices can be changed, but beware that the whole board is not isolated from mains voltage.
I got so sick of repairing these boards, or the motors, that I dumped the lot. I bought a 1/2 hp 3-phase electric motor, and a small VFD (actually for 2.2 KW). I had previously modified my mill to a toothed belt drive using the original motor (very simple to do - about one days work), The new 3-phase motor fitted in the same place as the original - I just had to drill mounting holes on a different pitch circle. The VFD was mounted in a box to one side of the mill, and connected directly to the motor via a protected cable. This instantly gave many advantages - soft-start, reversible, speed control from zero to max, short- and overload protection, and an RPM display courtesy of the VFD. The motor and VFD cost just over 150 Euros complete - less than the cost of a replacement original motor (and I'm sure a damn sight more reliable).
The whole mill runs very quietly now, with none of the old gear grinding. It was so good, I dumped the motor/electronics on my little 7x12 lathe (same as the mill), and fitted a 3-phase motor to that - it uses the same VFD, just unplug the mill and plug in the lathe - I'm not clever enough to use both together. A bit more mechanical work on the lathe, to make the reverse tumbler fit (Its still needed fro left-hand threads), and to get the toothed belt drive to fit, but nothing very complex.
It might be worth considering before buying and fitting replacement motors and boards which are just as liable to fail as the originals - and more expensive.