As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT ROTATION AND LIFT OFF GEAR WOULD NOT RETRACT AT THE SAME TIME GOT EICAS MESSAGE OF 'AIR GROUND FAILED'. RETURNED TO SFO AND MADE FLAPS 45 LANDING AT 0-50FPM SINC RATE AND 38270 POUND GROSS WEIGHT. SFP TO LAX. REMOVED AND REPLACED NOSE LANDING GEAR IAW EMB MM 32-20-01 OPS CHECK GOOD AIRCRAFT RETURNED TO SERVICE