As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - ACRID SMELL IN COCKPIT, ON TAXI OUT. FLIGHT ATTENDANT ALSO COMPLAINED OF ACRID SMELL. AIRCRAFT RETURNED TO GATE. REPLACED COCKPIT LIGHT BALLAST. AIRCRAFT GROUND RUN, NO ACRID SMELL NOTED AND LIGHT OPS CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.