Bad limit switch breaks MPCNC

Software / Firmware General
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I have an MPCNC Primo with SKR Pro V1.2 I purchased from someone. Worked when I bought it but later when I tried to auto home, it broke both Y axis carriages. This was caused by 1- the wrong connectors for the limit switches and 2- missing (not sure of this) missing VALIDATE_HOMEING_ENDSTOPS and DETECT_BROKEN_ENDSTOP.
What happened, due to the bad connector is one of the Y axis limit switches was not connected, telling the firmware that side was homed. The other limit switch worked so the firmware told that motor to go home. This resulted in the axis skewing, staling the motor and breaking/splitting both Y axis carriages.
I contacted the Marlin Github group they recommended enabling the above options. They suggested not having these enabled caused the problem. They also suggested setting max steps during homing as well though its not clear what that would do.
I thought having a max steps the second axis to home was allowed to move before a failure was detected. I haven’t checked to see exactly what the Validate/Detect options above do.
I’m not sure where to find the current config files being used by V1, for the SKR Pro. The information would be helpful as it would allow building the current version of Marlin.
That said, I think this will be a problem for any controller using dual endstops/switches.

The V1 and Marlin projects are simply amazing, V1 in particular since there isn’t a huge group supporting Ryan. Course that could just be my ignorance showing.

Regards,
Jim Brooks

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This is off-the-cuff (while I wait for my RaspPi cluster to uninstall a pod), and I will defer to @jeffeb3 and others for better info. If you go to Releases · V1EngineeringInc/MarlinBuilder · GitHub, you’ll find all the pre-configured releases for Marlin for various “supported” machines and controllers in the V1 ecosphere. It’s certainly not comprehensive, and there’s usually someone willing to take a stab at helping get any firmware configured for any controller, but these tend to be the ones that Ryan actually sells (or has sold), or are ubiquitous enough to warrant a “supported” configuration (including dual endstops).

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You might have had rhe endstops backwards too (x1 endstop near the x2 motor).

The best advice I have is to leave the firmware stock, but check with M119 before trying to home. Not every time. The machine shouldn’t pull itself apart like that anyway.

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Also wouldn’t hurt to verify NC or NO wiring and configs. NC is required for dection.

Even a crash from failed endstops at 48V/2A/16 microstep won’t break a primo… I know this for sure lol. But really, I suspect the plastic may be a little deteriorated if it broke that easy.