Electrocraft DDM Drive help and circuit sought

Background: 3 Axis CNC with Electrocraft DDM-019 drives halts midstream during normal operation. No previous occurrence of halting midstream. Drives, in Step/Direction configuration, connect to Reliance Electric H-3016 servos, as per manufacturers recommendation. Motors are conservatively rated for output load including during acceleration.

After halting the following applies whether the drives are connected to the CNC machine electronics or completely isolated from it.

X _Axis: normal.

Y_Axis: DM-019 front panel status LED green.
Cannot get RS485/RS232 communication with Bru Master 1.41 software.
No output voltage to motor (R,S,T) terminals.
Y motor checks out as normal when connected to above X_Axis drive.
Parallel connecting Y_ axis drive RS485 (or RS232) “sinks” communications to X drive.
Substituting the processor board from Z_axis drive brings up rapid red blink on front panel status LED.
No physical damage evident inside drive.

Z_Axis: DM-019 front panel status LED red-blinking (not rapid).
Can get RS232 (CP direct) but not RS485 communications with Bru Master. Bru Master displays on opening “Drive fault occurred. Bus Overvoltage Fault”. Pressing Reset button does not clear fault.
Bru Master Fault Status window indicates two alarms - Bus Overload and Thermal Protection Filter. Reset does not clear alarms.
No output voltage to motor (R,S,T) terminals.
No change to above when Z_Axis drive is connected to X_axis motor.
No physical damage evident inside drive.

Help Sought (by man alone):

1. Circuit diagram and component layout on DDM-019 or similar. Also, where and what is the “Thermal Protection Filter”? I note 2 Nana SY-10 components (green blocks each say 15x20x20 mm) which I am lead to believe are Hall Effect detectors.

2. Advice on what might have caused the above faults. The three DDM-019s are connected to a single phase 230V ac supply. I can spread connects to 3 separate phases – now regret not doing this earlier.

3. Are DDM series drives prone to supply over voltage problems, especially when connected to 220-240V ac? If so what are the over voltage mitigation options.

4. Recommendations on where to get the supplies repaired (I am downunder in New Zealand), if I be unable to repair them myself.

5. Should the drives be replaced (they have only done about 100 hours of operation and appear pristine – made the machine 10 years ago but got too busy to use it – but now fully into it!).

Thank you for your time.