As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE PILOTS SIDE PUSH TO TALK SWITCH WENT BAD WITH ONLY 548.0 TACH TIME. REPLACE THE BAD SWITCH WITH A NEW ONE. THE NEW SWITCH WAS BAD ALSO, THEN REPLACED THE NEW SWITCH THE SECOND NEW SWITCH TESTED OK. WHEN INSTALLING SWITCHES, WAS CAREFUL NOT TO OVERHEAT SWITCH.