Rambo 1.4a board gone bad?

After having a stepper overheating problem described here, I installed the latest firmware - V1CNC_Rambo_DualLR-2.1.1. My friend suggested hooking a stepper up to each of the ports to make sure nothing got fried. The stepper moves properly on all the ports except E1 (which is the right side Z-axis stepper (the one that melted the XZ_Main part). The Z port works fine moving the Z-axis, but when attempting to move the stepper on the E1 port, it starts moving and never stops. I have to disconnect the power. Is it possible the Rambo board was damaged? Is it fixable? Or is the better part of valor to just buy a new one? Thank you.

Hmm. Those boards have always seemed so bulletproof. I hate to hear of your troubles. If it’s repairable, then it will very likely be something very simple. If you end up needing another, let me know and I will part with one of mine.

I think that I would change up my firmware to control that stepper on the unused driver since there are six total. Or am I thinking of a different board?

Sorry, I still haven’t had my coffee and my brain isn’t quite ready for the day.

They are very reliable. But nothing is perfect. You can try reinstalling the firmware, but software usually either works out it is completely broken.

My guess is that it is either something wrong with the output pins on the arduino chip, or something wrong with that a4498 driver.

Personally, i would try new firmware. If that doesn’t work, I would get a new one and maybe try to rework this one as a future back up or project.

You could get an external driver and change the E1 pins to external pins.

Hi Jeff, Kyle,

Thank you both for the responses. I reburned the latest firmware just before running the last stepper test, but your advice has always been so good, I reburned it again. And it started working. I am so used to firmware upgrades running post burn verification tests that I did not think a failure could occur. I had used XLoader, 1.0 (2012), which googling is still the latest version. Again thank you Jeff and thank you Kyle for the offer of a board. I had a spare Rambo 1.3L, but I must have sent it to my friend when he was debugging a problem. I will buy a spare Rambo soon. I have a spare RAMPS and a Mini-Rambo, but this is a dual endstop setup, so I need the extra drivers.

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That is still a very surprising result. I am glad it is working. Sometimes this forum brings in the 1/10,000 results and it amazes me.

Try swapping the stepper motor cables between different ports on the Rambo board. This will help determine if the issue is with the E1 port specifically or if it’s related to the stepper motor itself. It helped me!

Hi Carl,

I had been moving the same cable stepper between all the different ports. It was only the E1 that was having an issue. I will power cycle it again and run through all the ports again before I reinstall it on the Lowrider2. Thank you.