I have put together a variant of DrRob's controller board using PerfBoard rather than StripBoard, and initial connectivity checking seems to indicating that the wiring is correct - however all is not well.
When i power up the board it draws current on the 24V side (just under .5A from a bench supply) for the first few seconds during which the X axis stepper is held in position - then it seems to shut down. If i then use the gCode controller (under windows) to try to adjust the x-axis the stepper will make some noise, but no actual movement - just rocks in place. The bench supply seems to indicate that it is trying to briefly draw current. Is it possible that since the bench supply is doing something odd in the setup? When it transitions from no current draw to attempting to move the stepper it makes an audible click (similar to when the current limit kicks in, but it is not going into current limit mode).
Also adjusting any other axis has no impact on the associated stepper, but it does make a (lower volume) noise on the x-axis stepper.
I am using the DrRob GRBL hex file from the wiki (0.7 version) and the newest implementation of the controller board with the pull up resister. Using a scope on the enable signal seems to indicate that the polarity is correct (pulled low when attempting movements on any axis), and the step and direction commands seems to be correctly activating. The steppers i am using are the Sparkfun 400 step/rev version in the original parts list.
Any suggestions before i start more detailed debug? I am hoping its an obvious brain-dead mistake that someone has already come across.
Thanks in advance for any suggestions.