I am not familiar with the bandit control but the favorite thing the BOSS machines liked to do is short the output transistors. From experience I know that one should not exceed 64 VAC nor 8.2 amps going to one of the axis. Also never press Emergency stop while a axis is running. The spike will short a transistor. Start there. You may resurrect it.
Also as the motors get old and weak, I lower the rapid thus the accel rate and it buys you a few more years of running.