Problem- G213V not working

[cristachelu]

Hello,

I'm new to this forum.
Here is my problem.
I got a Gecko G213V stepper driver 2 days ago.
I built the stepper tester on their website using 7414 inverter and I replaced the resistor with a potentiometer to adjust the pulse frequency.

I tried all microstep, half step, full step combinations with 3 motors
I could not get more than 100-150 rpm no matter how slow I was ramping up the speed.

The 3 motors I tested with were
(1)
Motor Frame size: NEMA 34
Holding Torque: 63 kg.cm / 874 oz.in
6.6V
3A
12mH
2.2 Ohm

(2)
Motor Frame size: NEMA 34
Holding Torque: 48 kg.cm / 665 oz.in
6V
2A
12mH
3 Ohm

(3)
NEMA 23
20 kg.cm / 277 oz.in
3.6V
3A
2.4mH
1.2 Ohm

With the big one (6.3Nm) while adjusting the potentiometer I got the fuse blown.
I replaced the fuse with the original part as per spec and now the green and red led are lit no matter what motor and configuration I'm testing
I have another cheap chinese driver which ran all the motors fine but slow but I cannot make them run again with the G213V

I'm not sure what "undestructable" means on gecko website. I handle it with enough care, didn't shorted any motor or driver output.

Did anybody experienced something similar with this drive?