What was found
AT FL 430, WITH PFD 2 SELECTED (RT SEAT FLYING) LT PFD COMMAND BAR TURNED BLUE ALONG WITH ALL TREND BARS AND COURSE INDICATORS. THE RED AIRSPEED TAPE DISSAPEARED AND THE ATTITUDE GYRO TURNED TO GRAY, VICA, BLUE AND BROWN. REPOSITIONED THE NR 1 PFD TO THE MFD POSITION, AND THE MFD TO THE NR 1 PFD POSITION IAW THE MM 34-25-01. OPS CHECK OF BOTH UNITS GOOD. MONITORED SYS FOR SEVERAL HOURS WITH NO DEFECTS NOTED.