As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(510901) STUDENT PILOT WAS FLYING W/CFI. DURING STUDENTS FIRST STALL PRACTICE THE WARNING HORN FAILED TO OPERATE THROUGH FULL STALL, CFI HALTED MANEUVER. TROUBLESHOOTING CONFIRMED THAT WARNING HORN WAS DEFECTIVE. REPLACED WITH NEW, OPS CHECK AND TEST FLIGHT WERE COMPLETED, OK PROBABLE CAUSE HAS NOT BEEN DETERMINED AT THIS TIME. (EA07200503884) (K)