If you are going to replace the connectors, do yourself a great favour at the same time and put some diodes on the return paths for all the coils. They will block any backwash from a locked on coil etc and protect those precious and obsolete spider chips

Thanks Gav, I have a 4 in 1 board to go in so that should take care of that. The machine as I brought it was not in any condition to fire up so at the moment I don't know if there are issues with the existing driver board. I just thought the 4 in 1 would be easier in the long run.