For assembling of this harware we need a good knowledge
in soldering of very small SMT components.
Some SMT Pads, has a gap of only 0.2mm, see the picture bellow!
The assembled unit must be tested with rDUNOScope Firmware
and if it works, is fine...
My experiences had showing, that the China parts like TFT Display,
does not always work!
It can lie on the defective Display or we have a soldering fault...
In this case we need to figure out where is our problem
and we need an oscilloscope!
For soldering of Stepper Driver Chip DRV8846 or DRV8825,
we need a special soldering oven, because this Chips has a Exposed Pad
for dissipation of heat! We can not solder this with solder pen,
because the Pad is on the bottom side of the Chip!
I think, the better way to sell this unit as tested and working assembly.
If someone wants to bild it himself,
no problem but on own responsibility!