Originally I brought a 3020 machine and that has lasted 3 years with very heavy use. It's the bearings and stepper motors that are giving up, the control board has always been fine.

Love the 6040 with the bigger work area and the control board seems fine so far, no issues with axis reliability.

I think I found the control board specs looks like it is a JP-3163B or variation of this. Looks the same.
Last night I rewired the inside of the control box to add plugs for Limit switches and Spindle direction / speed. I think I have found some documentation showing where to connect and it looks like I have to mess with some jumpers as well, so hopefully I'm making progress.

If and when I get this going I will do a post showing how it all worked.

Then I really need to finish my custom machine as the parts have been semi assembled for over a year now LOL