[Serhio]

Hello experts,

I would really appreciate if you could give some suggestions as for reason for the problem I encountered while trying to make things work.

I and my buddy who is the main brain in our endeavour were trying to put together the system including Arduino Uno board, a linistepper v2, and a stepper motor.
That was the first time we connected all the stuff together and it worked quite well. As soon as it worked we decided to make some changes to a program playing with delays and other setups.
For some time it worked fine but then we saw a smoke going from a linistepper board. We measured the voltage on the input and output and here is what we got:
input - 20 V
A1 - M+ 0V output
A2 - M+ 10,5V output
B1 - M+ 3,5V output
B2 - M+ 3,5V output

I may suspect that something is burned and needs replacement but I would definitely need some advises as for this matter.
Thank you in advance for the suggestions.

[James Newton]

Fried a power transistor. Replace all transistors as a set. Shouldn't cost more than a few dollars.

[Serhio]

Fried a power transistor. Replace all transistors as a set. Shouldn't cost more than a few dollars.

Thank you James, will definitely do and will post here how it worked.