As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, THE FLIGHT CREW HEARD A FIRE WARNING BELL WITH NO INDICATION OF THE SOURCE. THE AIRCRAFT CONTINUED TO ORD. CREW REPORTED THAT ON CLIMBOUT THRU FL200, FIRE BELL SOUNDED WITH NO OTHER INDICATIONS. RESET SYS, TESTED ENG'S AND CARGO SYS'S, ALL TESTED NORMAL.