Geeetech

I tried loading the marlin firmware onto the board with your ide, no change regarding the "7 commands" issue in Repetier.

so，I have a question。
1.i doubt that the firmware does not upload success，even it show “done upload ”
2.in your reprtier，you can set it like this： config》reset on connect 》disable

I found the problem, repetier reset the baud rate. That said, I tested the motors again, the z axis motors still do not move.

I'm sorry if this wasn't clear. changing the firmware did not work. the z axis motors still do not move.

Is there anything else that can be done, or is this a confirmed hardware problem?

If it is a hardware problem, then how does Geeetech go through the replacement process?

when the motor was working,you testing the following pins
the DIR and GND normal is 0-5V
the STP and GND normal is 0-2.2V
the RET and GND normal is 1.5V

When I tested the areas you directed, I got the following results:
the DIR and GND was a dud, .002 volts
the STP and GND was very low, .025 volts
the RET and GND was almost normal 1.25~ volts

I upload the stepper firmware in this post.
you only need to connect 12V power supply and the axis motor.
you test the voltage between the pins again.
waiting your reply.Best regards.

DIR and GND fluctuated from .01 to 5.1 volts
STP and GND fluctuated from 1.1 to 2.55 volts
RET and GND was only .143 volts

if the z axis motors still do not move.
The good news is I think we found the reason, maybe the chip 4982ET damage.
Also I'm sorry, we can't help you to replace the chip, May require you to replace the chip by yourself.
hope to be solve this problem, waiting your reply.
Best regards.

I'm sorry, but the z motors on the board are not moving.

The z motors on the board never moved. I had this problem from the beginning, the board came broken.

Is it possible to get a replacement to the board, since it came broken?