Dennis
Have you checked all the power supply voltages ?
If you hold the reset button in (if it has one) do the drives Lockup ?
Can you identify the voltage led that's coming on ?
If your encoders have power on them, Check with a volt meter at the +_ 10 volt terminals for voltage, Between CPU and Servo control.
Then turn the servo motor by hand and look for a voltage change, One way - volts the other way + volts ?
Chip