As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI, EICAS MESSAGE FOR THE LT REVERSER ISOLATION VALVE DISPLAYED AND THE THRUST REVERSER INDICATION CIRCUIT BREAKER TRIPPED OPEN. THE AIRPLANE WAS REMOVED FROM SERVICE. THE CAUSE OF THE EICAS MESSAGE AND TRIPPED CIRCUIT BREAKER WAS WIRE W756-503-24 WAS SHORTED TO GROUND AND BURNED AT BS 303. THE WIRE WAS REPAIRED.