Got this sorted eventually. When wiring the x axis one of the wires was labeled incorrectly. Checked x against y and z and picked up the discrepancy with the x wiring.
Subsequently the NVEM v2 just lost its firmware somehow. When starting Mach3 it kept asking for bin file. Emailed the seller. No response. I purchased via AliExpress they did nothing. Eventually found the v2 bin file on an obscure webpage along with several other useful files from novusun. That did the trick. Now working well.