Spark Max no lights except when connected by USB

On our 4-motor drive platform with Neos, one Spark Max suddenly stopped working with these symptoms:

  1. Shows no lights when on the robot or by itself connected to 12V power
  2. If we connect Rev Hardware Client to one of the other 3 Spark Max’s, we see the rest of the CAN bus, but not the problem Spark Max.
  3. Shows lights when connected by USB to the Rev Hardware Client, and we don’t see anything abnormal in the hardware client, but when on the robot, hardware client does not show the rest of the CAN bus. Re-flashed firmware, restored factory defaults, and made other changes, but nothing fixed issue 1 or 2.
  4. Replaced with a new Spark Max and the above problems went away.

This Riolog image shows an error when the problem began. Notice that there is a message that “GetEncoder was already called.” That’s accurate, and we fixed that redundant call to GetEncoder. Hoping that call isn’t what caused the Spark Max to fail.

What does the Hardware Client say the CAN ID is when plugged into USB? Does it say 14?

If so, your SPARK Max is probably faulty.