[Al Skierkiewicz]

Sarah,
Does the fan stop turning when you try to advance the motor? I know this may sound dumb but are you absolutely sure the wiring is correct? It is very easy to swap input wires and it is equally easy to swap input and output.

There is a varied list of failures for 884:
1. Metal flakes inside from drilling, deburring or other mechanical work on the robot.
2. Wire polarity flipped (black with red or + to -) This usually results in little explosions of the power FETs.
3. Input swapped with output, results as above.
4. PWM cable not fully inserted. There should be only about 1/8" of the block showing above the molded plastic. Easy fix but watch for bent pins on the PWM cable. Also try swapping a working PWM cable to the non working Victor.
5. Improperly crimped power wiring. This can result in the fan turning until you try to make a motor move. It can easily be fixed. Wiring can be loose at the 40 amp power block, at the Rockwell terminal block or at the Victor 884. Usually this is not a catastrophic failure and easily remedied. Check all wiring by pulling, if the wire moves inside the contact or pulls out of the blocks then just reterminate.