Can't get Y-Axis to move with Marlin firmware

Just as the title says. I feel like I have tried everything. I am compiling the firmware for Marlin on a Megatronics board from RepRap. That shouldn't be relevant, because I have validated that it is a firmware issue (and not a pin assignment/hardware issue).

When I turn it on, the Y-axis is active and just constantly holding. The stepper driver on Y-axis gets pretty warm constantly holding (as does the stepper motor).

When I swap the pin assignments for Y and X then the physical Y-axis moves fine when I manually change the X-axis so I know all the hardware and pin assignments are correct.

All the endstops are correctly reporting open (Z is BLTouch but that is also working).

Relevant software endstops are currently disabled, and default homing position is set to 50 to make sure it doesn't think it is at the bounds on boot.

I have a test firmware that checks all the endstops, temperature, and servos, and all servos work fine. As a sanity check, pin assignments match what is in the pins file.

Does anyone have any idea of what in the latest Marlin firmware would cause a software condition to just hold the y axis and not move? I should note that when I try to manually move it in Repetier-Host it shows that it is moving. When I try to give the home command, no movement on the Y but Repetier changes from red to black indicating it received confirmation of homing.

I am completely out of ideas at this point.

• Which Megatronics board do you have? What are the stepper driver types? Have you tried to use a free stepper slot (there are 6, so unless you have X, Y, Z1, Z2, E1, E2, you should have at least a spare slot) and or a different stepper driver? Is the driver correctly positioned? Just some ideas for you to play with!
– 0scar
Feb 19 at 8:59
• yeah I have actually tried using a free stepper driver slot. Anything that was tied to the logical "yaxis" wouldn't move. I re did the whole firmware with the default config file and it worked. It was some problem with the megatronics default config file Feb 19 at 22:55
• Please accept an answer so that the question doesn't pop up automatically by the system, thanks.
– 0scar
Mar 28 at 12:14

There is a problem in the Megatronics default config file. I used an other default config file and it worked!

• Did you spot the problem in the defective config file?
– 0scar
Feb 19 at 22:57
• I have spent sooo many hours going through that same config file over and over. I even found multiple different versions of it, and started from scratch, and it always had the same problem. As soon as I used the default it was fine. So no I couldn't figure it out Feb 19 at 23:03
• Okay, thanks! Would have been nice to know! 😃
– 0scar
Feb 19 at 23:04

I ran into the same problem. After looking into the pin layout for the board I saw the following:

#elif EXTRUDERS <= 2
// Hijack the last extruder so that we can get the PWM signal off the Y breakout
// Move Y to the E2 plug. This makes dual Y steppers harder


This prompted me to move the stepper driver and the motor cable to the E2 connector on the board. (The one on the other side of the X connector, Order is Z,Y,X,E2,E1,E0) That worked for me.

So, you could move the stepper driver and motor cable. Or you could commment/remove that code from the pins_MEGATRONICS_3.h file