Assembled an EZ board. All went went well and checked out each step to instructions. 5v regulation at 5.05. 24 volt as well. set ref voltage to .42 for 3 amps. Set jumpers to 1/2 step. Soldered wires to stepper motors and rechecked colors and used meter to ring out the motors. All checked good. Wired power supply and rechecked all voltages. No change. Cooling fan ran well. Motors locked up. Then- apparently a stray piece caused the smoke to leak out. Z chip burned and damaged trace to jumper. Board was dead. replaced smoking hot transistors and got 5v and 24 volt back to same values. replaced all three driver chips and repaired trace. No lockup. Any thoughts?
Once the ‘magic smoke’ is released all bets are off.
I’ve tried to fix boards that have had a catastrophic failure (as opposed to a chip just ‘crapping out’), with very little success. My best guess is that undesired voltages seem to go everywhere and mess up everything. Contact me offline (firstname.lastname@example.org).