As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT # 578, SFO-FLL. AT CRUISE SMELT ELECTRICAL FUMES AND HEARD SQUEAL. ISOLATED THE BLOWER BY GOING TO OVERRIDE ON EXTRACT. SMELL DISSIPATED. THERE WAS SOME VIBRATION NEAR EXTRACT FAN. AFTER LANDING EXTRACT FAN LOUDER ; REMOVED AND REPLACED AVIONICS FAN 18HQ AMM 21-26-51. OPS CHECK GOOD. A/C GOOD FOR SVC.