As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - DURING PREFLIGHT INSPECTION, FLIGHT CREW NOTED ACRID ODOR IN BOTH THE FLIGHT COMPARTMENT AND THE CABIN. INSPECTED RADIO RACK, FLIGHT COMPARTMENT INSTURMENTS, AND CIRCUIT BREAKERS. NO DEFECTS NOTED. COULD NOT DUPLICATE. AIRCRAFT OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.