I soldered and put the jumpers, flashed the arduino mega, it works fine.
Was it the slp/rst?
yeah. those to pins must be soldered together and some jumpers on the black and white side, 3-4, i don’t remember. The machine is working, without limit switches, with lasergrbl. Ramps 1.6+ is running two nema 17 with one drv8825, fine for the moment, anyway nice board. oh, and cooling for the mega, today stopped working because got hot, forgot about the cooling. Before, i tried to run the cnc with an btt skr 1.4 and marlin 2.0.9,1 and in the and switched to ramps, with grbl firmware it’s much better.