Hi All...

I am currently trying to replicate the POSIX design linistepper. I am using the transistor aligned design posted on the lini website and i am having no joy.

I first built the circuit and found that the one transistor would remain on constantly and begin to smoke. I though that the pic maybe stuck and thus replaced the sense resistors and all the transistors. Programmed a new pic with v2 asm file and powered up again.

This time i get nothing, no smoke, nothing, the motor is not even energized, i can turn the motor with my fingers. there is voltage at the transistor but it doesnt seem to move onto the motor coils. I have also now changed the BC337's and still nothing.

What would be the route to troubleshoot this design? How would i test to ensure that the pic is behaving has needed? Any help would be greatly appreciated.