K8005 voltage problem

Kits PC Related Projects
1

When I apply 24 Volts DC (regulated) to the stepper board something is burning out. I replaced two transistors (T7 and T11) which fixed the problem. I reapplied the 24 volts and something burned out again. Any Ideas? The board says it is rated to 27 volts.

I saw smoke coming from the board around T 11 again.

2

It’s strange that only these 2 transistors are burned.
Did you test the card already with the included 12V motor ?
Maybe the motor take’s to mush current/phase ?.
Max 0,5A is allowed.
Wish motor are you using + purpose ?