As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED- AFTER ROTATION WE RECEIVED LDG AIR/GND FAIL EICAS. FO TRIED TO RAISE THE LANDING GEAR LEVER AND IT WOULD NOT BUDGE. THE GEAR REMAINED DOWN FOR THE DURATION OF THE RETURN. WE EXECUTED THE QRH FOR THE ASSOCIATED MESSAGE. CORR ACTION- MX TROUBLESHOT TO NLG SERVICING LOW REQUIRED SERVICING. PERFORMED EXTENSION AND RETRACTION TEST ALL TESTS GOOD.