Troubleshooting non responsive machine- Mach3/Syil x4

[Doddy]

All very interesting. I'm getting confidence with your meter. Pin 3 is an output from the PC, likely pulled-high on the board - so measuring it disconnected from the PC at 5V makes sense to me.

Right, let's have some fun. Only proceed if you're happy that you can safely do this with your computer printer port (or at the end of the cable that you can plug into the printer port) - rather depends on whether you can insert a pin or socket (I forget) over/into a pin without cause a short circuit. If you have a spare DB25 connector of the correct gender it's a lot easier.

FOR CLARITY - this is done only with the computer, not with the machine connected.

What I'd be interested in is whether you can connect the pin 11 on the PC side to 0v or 5v. You don't have 5V available as-such on the parallel port, but you do have 0V. A cunning alternative is to use the X-DIR OUTPUT from the PC and use this to drive the E-STOP input, simply - short pin 17 and pin 11 on the DB25 connector - without shorting any other pin!!

If you're satisfied that you can do this safely/sensibly, disable the ESTOP input on the mach3 Inputs, then you can use cursor left / cursor right to change the e-stop signal on the printer port. Use the diagnostic screen to verify the state of this (I've not used mach3 for a long while - I expect you can also see the state of the Direction signal on P17 as well).

If you can verify that, then I think the problem can be localised to the BOB.