43,
Just need to make sure you did the following..
1. Unplug the robot from the power supply.
2. Turn the power supply on as if the robot was connected.
3. If the circuit breaker pops, it has to be internal to the power supply. (Buy a new power supply)
4. If the breaker does not pop, connect the robot and turn on the power supply again.
5. If the breaker pops, it pretty much has to be something in the robot..
In the big picture, if it only pops with the robot connected, I would think that the robot is the problem, but depending on the design of the power supply, it might not work at all, unless the robot is connected.
If you have to send it back for repair, they will want both the robot and the power supply,
When the motor box floods, then the only fix is a new motor box.. The motor box might not be flooded and maybe it is something else, but.. based on your original question, I would have to assume fixing anything inside the motor box would not be a DIY fix...
Thanks,
Jim R.