As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF UPON GEAR RETRACTION, THE GEAR WARNING HORN SOUNDED. IT LASTED FOR A COUPLE SECONDS THEN GEAR UNSAFE LIGHT (RED LIGHT) WENT OUT AS WELL AS THE HORN STOPPPED. ALL GEAR INDICATIONS AFTERWARDS WERE NORMAL INCLUDING THE 150K HORN WARNING CHECK.