Returning MPCNC user with X1 issue

Mostly Printed CNC - MPCNC Troubleshooting
#1

Hi all,

Back from a long hiatus of not using the MPCNC.

Has anyone encountered issues of an end stop inputs on the RAMBO stopping working? Spent quite a bit troubleshooting why the auto homing no longer works. Was skipping like crazy on the X axis. What I found is the x1 (x-min) rear is not reading the value of a switch so during the homing function it assumes it’s already at the endstop and will not move. I verified the switch is fine and even swapped around with others. All 5 switches and cabling are fine and every port works except X1. There were no hardware changes or updates since I had the system powered off. Literally just stopped working while not used. Verified all values by using M119 to read the states directly after figuring out the stepper was not moving.

I’m not sure of any alternatives (aside from manual homing) other than replacing the entire board, but checking for thoughts or suggestions?

#2

I know you said wiring and the switch was fine, but I would suggest taking another close look. It should be NC, so a broken wire or stich that can’t close would look to the MPCNC like a triggered switch. Another test you can do is to short the S and (-) (not the (+)) and check M119. It should say open.

#3

Hi Jeff,

Yes, I manually verified each switch and wiring (both sides) and even created a new stand along jumper to 100% verify (and tested jumper on x2 and y1 just for validation. The X1 just does not read any input state.

this is what I always get regardless of the jumper / switch state for the rear X.

Recv: Reporting endstop status
Recv: x_min: open
Recv: x2_min: TRIGGERED
Recv: y_min: open
Recv: y2_min: open
Recv: z_min: open
Recv: z_max: open

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#4

If I need to replace the controller, is the Rambo still the recommended go-to? Haven’t kept up with the forums for a while. See the new parts version, but wasn’t needing to reprint as mine’s been super solid and working great and haven’t seen much on boards.

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#5

That is strange.

Yes, The rambo is still a good choice. The new choice is the skr pro v1.2. But I’m not sure if is significantly better than the rambo. They are both great.

Maybe someone else will come in with something I’ve forgotten.

#6

You might take a look at this topic. OP had a burned out endstop pin, and he was able to fix his problem by re-assigning the endstop to a new, unused pin. The same fix might work for you.

#7

Finally back to CNC time and was ready to order complete replacement Rambo but out of stock. Any ideas on ETA if this is short term or do I need to try a SKR (and start reading to see if the wiring will match up to swap)? From the previous comment in September (time flies!) looks like moving towards teh SKR Pro is not a bad choice.