As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDING GEAR WOULD NOT RETRACT ON TAKEOFF. WITH GEAR HANDLE UP, RED INTRANSIT LIGHT ON, GREEN DOWN AND LOCKED (3) REMAINED ON C/B B2 POPPED. MAINTENANCE FOUND DIODE BLOCK SHORTED. SWAPPED PINS A-B TO SPARE DIODE AT GC2 BLOCK IAW AMM. COMPLETED OPERATIONAL CHECKS OF LANDING GEAR CONTROL SYSTEM IAW AVRO AMM 32-30-00. ALL CHECKS GOOD.