As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SWITCH ACTUATOR IS CUTTING A GROOVE IN THROTTLE RAMPS. AS IT WEARS, IT CHANGES WHEN THE GEAR HORN SOUNDS TO A POINT WHERE IT WILL NOT SOUND AT ALL. WE MAINTAIN 5 NEW AIRCRAFT OF THIS TYPE. ALL HAVE HAD GEAR WARNING PROBLEMS. SUBMITTER RECOMMENDS CHANGING THROTTLE RAMP MATERIAL TO SOMETHING HARDER THAN ALUMINUM.