Hi Again
1 step forward 2 back sort of day.
My contactor was 110v, probably run from a leg of the 110v 3 phase used for the servo motors.
It only controls motor rotation so I have replaced it with a 240v single coil one with NC and NO contacts and set it up to default to CCW (the lathe is slant bed so everything bar drilling etc is CCW)
The transformer did not have any shorts, so with fingers crossed powered up.
I had immediate rotation of the spindle, albeit slow and uneven, even though I was not applying any signal voltage .
Then the 'TRIP' LED on the Gemini board came on and it stopped.
Unfortunately after 2 minutes the C2 capacitor started smoking.
They obviously have a limited life because I have read a couple of times about people powering up an old one of these boards and this happening.
I have ordered replacements for C1 and C2 (RIFA PME271M as a replacement for the apparently discontinued RIFA PME261 fitted, both 0.1uf and should be suppression capacitors)
They are only 51p from Farnells so not much lost if the problem is deeper than an old capacitor with internal breakdown.
If that works OK, I will try applying a signal voltage across screws 2 and 7.
Given your experience it will be a low one to start with!
cheers
Melee