[Kevin Sevcik]

I'm really leaning towards a sneaky electrical problem in the high current path as well. As noted, it's really rather difficult to kill CIMs, especially to kill them as much as you claim to have done. Having a robot act strange under high current draws is pretty darn easy, though. The fact that your other motors are working fine doesn't really change anything, as they don't sound like they're drawing very much current at all.

I'd really, really recommend checking you connections, as it's really the only thing those two systems have in common. I can't imagine your launcher motor was running for the exact same time your drive motors were. I'd bet it was running 25% of the time or less, so it should have deteriorated much more slowly.

If you really can't be bothered to check all the connections first, you can do a quick check with a pair of multimeters. Measure the voltage across your battery and across the V+/V- terminals of your launcher's speed controller while the launcher is loading. I'd recommend doing the drive wheels as well, but you need some way to safely load them while the robot isn't moving. The difference you see is entirely dependent on how much wiring you have and how good your connections are, but I don't think it should be more than 1.5V. Maybe 2V. I'm sure the other experts in this thread with have good suggestions for values, but you're dropping 2 or more volts on the way to your speed controller, you definitely have a problem in the power path.