Good advice. I have checked the cables by swapping the steppers at the board end but haven't checked for dry joints yet. I will do so before I attempt anything drastic.
I've used Pololu A4988 boards in various projects over the years and I've always heatsinked the chip. The Rambo has no heatsinks and there is no real airflow over the board. Could this be related? Obviously too late now if so, but it might prevent it happening again. I only got about 3 weeks use out of this board and Ultimachine's reputation is much better than that. So I'm assuming its a dodgy one off or the 'Official' Prusa i3 has cooling/airflow issues - see link. Is that fair?
John
I've used Pololu A4988 boards in various projects over the years and I've always heatsinked the chip. The Rambo has no heatsinks and there is no real airflow over the board. Could this be related? Obviously too late now if so, but it might prevent it happening again. I only got about 3 weeks use out of this board and Ultimachine's reputation is much better than that. So I'm assuming its a dodgy one off or the 'Official' Prusa i3 has cooling/airflow issues - see link. Is that fair?
John