Digital sidecar PWM controller failure

[Oblarg]

Recently, we built a practice robot to get in some more driver practice and test additional mechanisms before our next regional. The robot was working fine, until suddenly the Jaguars started reporting that they were receiving no signals. After a few hours of troubleshooting, we had no ideas as to what could be wrong, except that the relay lights were on but looked as if they were receiving half power.

A day or so later, we procured a second DSC, and wired it. The robot worked fine for about 5 minutes, but then the jags reported again that they were receiving no signal. The relay lights also started lighting up as if they had half power. We took the cover off of both of the DSCs and found that the C6 capacitor had been knocked off of both, but we found later that this is a known issue that should not result in DSC failure. We also noticed that the PWM controllers on both smelled very burned. We've checked every PWM cable for resistance, and all are correctly isolated. None of the power wires on the digital inputs are connected. None of the servo jumpers are in.

Does anyone know what could have caused this, or what steps we could take to avoid it in the future? Were are heading to North Carolina with our only remaining DSC, and would like to avoid killing it.

[Al Skierkiewicz]

Eli,
When you break something off the board and it starts floating around inside (like it will this year) then you can expect it will end up somewhere where it will cause some damage. Shake your remaining DSC and see if anything shakes around inside.