I'm writing this message because I am desperate.
I built a cartesian printer and have a serious problem with steppers. All is OK except that.
Here's my problem :
When I connect one stepper to my RAMPS 1.4 and clic "start Motors" in Simplify 3D, the stepper makes some noises but does'nt want moving.
Wiring is OK (I spotted the two pairs : red/blue, green/black). I even tested all possibilities to connect to the RAMPS.
Power is OK : 12V 50A.
On my driver DRV8825 Vref is OK (I tested to turn the potentiometer : stepper makes differents songs but does'nt move).
All 3 jumpers are connected on the board (I tested without the jumpers : same result).
I also tried to connect a 4.7K (and a 10K) resistor between sleep and fault pins on the driver but no more result.
Do you have any idea to help me ?
This problem appears on all axes. So I make theses tests with one stepper (but tried some steppers to eliminate the stepper problem) and disconnected all others modules to the RAMPS.
I specify that motor doesn't move but it is very hard to turn manualy when it is started. So current should be OK.