As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDING GEAR LEVER WOULD NOT RAISE ON DEPARTURE. PULLED OVERRIDE TRIGGER, GEAR RAISED NORMALLY. THRUST REV ISOLATION VALVE LIGHT ILLUMINATED AND CONFIG WARNING HORN SOUNDED WITH FLAPS TO ZERO. RETURNED TO DAL. REPLACED LANDING GEAR ELECTRICAL MODULE AND OPS CHECKED PER BOEING M/M.