As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING CRJ SERVICE CHECK ON ROUTINE MAINTENANCE. THE MECHANIC WAS UNABLE TO PUSH-IN EITHER LT OR RT (FIRE EXT PUSH-OFF) SWITCHES/PBA. BOTH PBA ASSEMBLIES FOUND CONTAMINATED (CORROSION) WITH A WHITE POWDER DEPOSIT. REPLACED BOTH PBA ASSEMBLIES. AIRCRAFT FUNCTION CHECKED AND RETURNED TO SERVICE.