Has anyone experienced an all-out hardware failure with a Quantum PLC? Program and communication lost. Unable to even connect serially over Modbus.

If so, were you able to determine the source of the failure?

 

Yes, under warranty, had to install replacement unit and install backup copy of ladder logic , Feb, 2001. 1 out of 10 at the plant, it was a 140 CPU 434 12A. Never discovered the cause of failure. had tried to power on/off, but Ready light was not restored.