Z axis homing problem after firmware upload

Hi everyone.
I have simple 3d printer that it was running perfectly. I decided to upload latest firmware and it failed than I re-upload my previous firmware.
problems started after that moment. as I said it was running before that.
now when I want to use auto-home, machine makes x-axis homing and y-axis homing normally (I mean it touches the endstops and proceed to next step). then head goes to center of the printer to home z-axis, head just travel up.
on the lcd, it seems homed all axis but z-axis stays obviously not homed.
when I try z-axis to move up and down manually, it is ok.
I have tried lots of things:

  1. disable parking feature
  2. lower the value of z feed rate
  3. replace endstop
  4. replace cables
  5. playing with axis rotating configs.
  6. I have 2 z-axis driver and replace their slots
  7. also replaced with y-axis driver
    none of them give positive result.

if you can help me out this, I will be thankful.

1 Like

Hi Beyazit,

Are you sure you have flashed the right firmware for your specific machine? Was it “pre-fab” firmware, a " *.bin " file? You’ll never be able to see any errors that might be in it, since you can’t inspect the contents of a .bin file. Building your own firmware using a download of Marlin and editing the configuration.h file yourself, you can be sure that the firmware you build from the edited file accurately reflects your hardware. I used “pre-fab” bin files at first, and ran into a similar problem (X&Y home fine, Z shoots to the center of the bed and goes up then shuts down the printer with unspecified errors) Sometimes you can find configuration files pre-build, as “configuration.h” files (Configurations_release_2.1.2.1 in my case, since I’m running Marlin THEN you can look at the .h file and be certain that what needs to be #defined IS defined, and things that need to be disabled ("commented out with leading “//”) are commented out.

thanks kharrisma:
actually I have found the problem. it was in the mks gen l v2.1 board. seems like, D18 and D19 pins are conflicting with serial port config. when I disable the serial port, it starts working. the point was previous firmware was running before. I am not sure, if I did change the serial port before.
well, again, thanks. problem solved.