Spindle "logic" DOA

I’ve finally gotten around to upgrading my Shapeoko 2, and everything seems to be working. But the “logic” mode never provides power to the spindle.

In a brief attempt to troubleshoot, I bypassed the controller altogether and jumped the logic contacts with a bit of wire, and even that doesn’t work. So I figured there’s a dead relay or whatnot.

Taking the power supply back apart, I see the relevant MOSFET assembly has a contact that isn’t soldered but that’s just the heat shield and I assume irrelevant?

I’m just a software guy, can someone who’s a little more EE help me diagnose this? Asking Inventables to just send another part is a last resort, since they take a long time to get here to Europe.

Double check your connections on your arduino pins, what version of grbl are you using? remember the pins change on 9

There are some that did have trouble with a MOSFET and the spindle control. Inventables sent out a new one if I recall correctly.

My suggestion is to contact them via email and they will get you sorted… help@inventables.com

I think this thread is where I saw it, but there may be others:

I’m on a version of Grbl 0.9 … not sure it’s “i” but my next step is to re-flash anyway.

I was hoping that shorting the logic pins together would eliminate the Arduino entirely. Is that not true?