Problem with a MESA 7i76

Ok thanks for the quick feedback. I've tried but nothing happens! The oscilloscope we had in the lab is not working so I cannot test the pins.

I would try making the step length longer than 1 usec (1000 ns)
1 usec will fail on 95% of step drives

5 usec is usually a better starting place

I've also tried your solution but still no results.

No outputs from stepgens 0..3 could also be the result of a damaged 7I76
(the first 4 stepgen outputs come from 2 chips, 1 for the + step/dir outputs and 1 for the - step/dir outputs)

Do the direction outputs work? (check + and -)
what are the output voltages?

I've checked the dir outputs: for the first four motors the outputs don't switch (always at 5V), while the dir works for the fifth motor (switch correctly from 5V to 0V and viceversa).
The 7i76 is new, I really hope it's not damaged!

did you check the + and - outputs?