What have I done!

[i2i]

Make sure the ground of the driver board is connected to the ground of the parallel port.

[artmin]

Make sure the ground of the driver board is connected to the ground of the parallel port.

Checked the ground and it is okay. Unfortunately I think JAZZCNC is correct. I installed the new PP card & lead and it's doing the same rubbish.

I have contacted Heiz and they have offered me an upgrade to the new Zero3 controller. It is available off the shelf in Germany for 360 Euro + VAT (19%) + shipping. It is a direct plug in replacement, so for the sake of speed & my sanity, I'm going to pull the trigger on it.

I'd still like to rebuild the old unit with CW5045 drivers & BOB as a direct plug in backup, install Mach on the spare PC and get learning.

Many thanks for all your help!

Gavin