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Totally lost control of RUMBA drivers....due to a Stepper??

Posted by bolsoncerrado 
Totally lost control of RUMBA drivers....due to a Stepper??
March 12, 2017 01:59AM
Let's see if i can explain myself correctly enough:

I have a printer with a RUMBA board and MARLIN 1.1RC7C in it that was working fine, until the other day that it was starting to perform weird heating issues. By rebooting octoprint and resetting the printer, even letting it cool down for a while, I managed to heat both extruder and bed fine. Then I tried to extrude filament but the motor didnt respond.

Next step was taking a multimeter and finding out power delivered to both hotend and heatbed was on the 11V range so I raised the powersource controller a bit, now getting close to 13v. Hotend and heatbed run just fine so far.

HOWEVER, returning to the motor in the extruder, I still find it does not move. The rest of motors, XYZ run just fine, so I think, let's swap E to the Y connector on the RUMBA and let's see if it's just a wiring issue. Motor on extruder would fail too...

I check continuity on all the extruder motor wires and continuity is OK.


Thinking its just a temporary "saturation" moment, I try with either X and Z with the extruder wires....

Result now is NONE of the XYZE motors work now!! I get "echo:busy: processing" when trying to move any of those repeatedly...

So question is: can a MOTOR, whose wires were reporting continuity, FRY the DRVs on the motherboard without heat, noise, spark nor smoke!?


what else am I missing here?!?!?!

I don't want to swap the board and find out the motor on the extruder is a MB burner!

Thanks for any help!!!

Edited 2 time(s). Last edit at 03/12/2017 06:50AM by bolsoncerrado.
Re: Totally lost control of RUMBA....due to a Stepper??
March 12, 2017 03:51AM
A damaged motor would only kill the driver, not the controller.
What do you mean with continuity on the motor wires? A shortcut is continuity ( bad ), but a coil has a small resistance ( good ).

WHY did the voltage drop to 11V? Do you have problems with the power plugs? What made the controller get hot?


"echo:busy: processing"

Where did that come from? The firmware usually doesn't know if anything is wrong with the drivers or steppers. It just fires step signals. Did you fry something onboard that keeps the CPU from sending the steps?
Re: Totally lost control of RUMBA....due to a Stepper??
March 12, 2017 04:09AM
OK i'll reword it... It may have killed each driver I have connected its wires onto. Question is HOW?

And...HOW can I check if its the motor the faulty one or the wiring up to it that has a short or something?

The voltage drop to 11V is not a fact, as I never checked the voltage on this printer before, probably came "underrated" from factory.
Controller is fine.

Once again, nothing seems fried to the eye, no smoke, no sparks, no cripping noise, no smell, no nothing that makes you think you fried something. The echo:busy: processing comes from Marlin each time I try to send several movements at once, but stays there "almost" indefinetly.... I do recover control on the board after a minute or so, but steppers no longer work.

So initial question is once again how do I test either / both the particular wiring or extruder motor for faults without actually frying anything else, either in this board or a new one.

EDIT: Just for reference, I replicated sending multiple QUICK command sucessions (move X move Y move X move X move Y move Y move X move Y move Y move X etc.) to a clone printer and I couldnt get marlin to drop a single "echo:busy" moody smiley???????

Edited 1 time(s). Last edit at 03/12/2017 04:10AM by bolsoncerrado.
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