We recently shipped out two Fanuc A16B-3200-0040 boards to a customer and upon installation, they received a Fanuc CHECKSUM error on their control. Here are the notes that we use to troubleshoot this Fanuc error which can be used to try and solve the problem.

There are two common causes for this problem.  The first and most likely is TP communications.  If you see 3-5 “_” appear under the checksum number, and no red LED’s on the CPU, then this is the problem.  This means that 1/2 the communications signal is missing.  Swap the Pendant and cable (Cable is probably crushed or cut), and everything should hopefully be great.  There is a possibility of damage on the CPU side, however.

MRO Electric and Supply has new and refurbished FANUC CNC and FANUC Robotics parts available. We also offer repair pricing. For more information, please call 800-691-8511 or email sales@mroelectric.com

The second is a corruption of software on the CPU.  This will result in the middle red LED (going from memory, so it might be a different LED) on the CPU turning on.  The only way to recover from this is to dump in an image, or reload core & put in your most recent backup.  Corruptions can occur from the backup battery being dead, noisy power being supplied, or any major power glitch while the system is on (power loss, lightning strike, etc.)