What causes an INF3 internal serial link fault on the ATV61 and ATV71 drives?

Issue:
What causes an INF3 internal serial link fault on the ATV61 and ATV71 drives?

Product Line:
Altivar ATV61 and ATV71

Environment:
All models, all serial numbers

Cause:
Communication fault between the internal cards   

Resolution:
Check options 1 and options 2 in the Identifications menu. Check to see if there is an error reading the option cards.
Check the internal connections. Check for loose or improperly seated connections and connectors.
Inspect/repair the drive.