Hi Richard,
Do I presume the stepper motors are not powered (can be rotated by hand), - if so check that the main power unit is giving the correct voltage (30V DC). I believe the stepper driver IC'c have a low voltage lock out.
Peter.
SC 420/2, Industrial VFD spindle from StoneyCNC
UC100 + UCCNC
Cut2D, Autosketch10, Draftsight, Eagle 9.5.1
There is no problem, however simple, that cannot be made more complicated by thinking about it.