Basic configuration for a chinese 6040 cnc router please

OK, sounds like my one, need a picture of the case front, rear, board(s) (incl VSFD as well) and the URL you bought it off. Not all 3163B's are the same there are generic clones which is what I have. Yes the power feed to these boards is 12~30v volts so on the LHS rear is the power in so you dont need to supply 5v to it unless you want to. My board has I think from memory 4 jumpers and not 3 hence its a "generic" clone with no exact manual. I think from memory the jumpers are etched on the pcb?

The history of the machine is unknown. I'm trying to figure it out to get it to work with LinuxCNC and off of Windows-Mach3.

Furthermore this machine has been modified to have a second, remote, Estop box at the end of a cable running from the main console.

The JP-3163B board is the single-DB25-port version and has an internal 24V cased power supply which however is disabled by the E-stop.

I'll attach my interpretation of the wiring tangle:

Ok so its sounds more and more like my setup. My one is single DB25 also and it works fine with Linuxcnc parallel port though the estop doesnt yet work. I bought this aliexpress pci card which works OK. www.aliexpress.com/item/Great-Q-1Port-I-...-to/32831133280.html

Pics of my machine as I am installing / modding it. One is the circuit diagram of the board, except my board seems to have 4 jumpers and the diagram shows 3. www.facebook.com/photo.php?fbid=21422512...14589&type=3&theater

I found a picture of the Chinese under the jumpers (from your build probably) and fed them into an online Chinese OCR program, and got the following, top-to-bottom (JP1-to-JP4?, in any case, JP1 has '5V' in the name, as expected for a '5V selector'):
JP1 "Internal 5V/external isolation"
JP2 "enable On/Off"
JP3 "air-cooling On/Off" (fan?)
JP4 "analog On/Off"

Nice one.... "Fan?" could be the Q is then which are the fan output terminals, that should be fairly easy to test for with an ohmeter and (what voltage comes out) PS cant see any obvious terminals in the pics I have. In my case I just re-wired right off the PSU to 2 new 6025 fans. The existing driver board's fan actually came off the VFD board would you believe! but the VFD itself had no forced cooling, like duh. Wiring was an utter mess and dangerous which I have fixed.

"analoge on/off" vfd speed control? I cant think of anything else.

@clunc I have the SXCNC 6040 w\JP-3163, do you mind sharing your stepconf setup? Thank You!

@willkallio After getting that machine to run LinuxCNC within a day, as I fully expected, I got drug down a rabbit-hole of trying to rewire and reconfigure it to "fake-out" a Tormach interface card with a bastardized version of LinuxCNC. What "success" looked like was never clear, and after three unpaid weeks, I ended up leaving the project to the "geniuses." I no longer have access to the machine, and I am guessing that my working stepconf was discarded.

However, I can tell you that my basic approach was to trace the wiring out to see which signals had to be on which parallel-port pins and then using the stepconf wizard to start trying to move the stepper motors.

Curious if you had any luck with your 6040? Any way you could share your stepconf by any chance?

6040Zs differ in the controller used. I cant upload pictures as they are two large, sorry.