As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BEFORE FLIGHT, THE CREW REPORTED BOTH CAPTAIN`S DISPLAY TUBES FAILED, THEY RETURNED TO THE GATE FOR MECHANIC. MECHANIC SWAPPED THE DPU-84 DISPLAY PROCESSORS AND ALL DISPLAYS WERE OPERATIONAL, WITH NO FURTHER DISCREPANCIES NOTED THE AC WAS RETURNED TO SERVICE. (K)