As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 AC GEN CAUTION LIGHT ILLUMINATED BEGINNING INTERMITTENTLY AT APPROXIMATELY 20,000FT LIGHT EVENTUALLY REMIANED ILLUMIATED CONTINUOUSLY INCLUDING AFTER COMPLETION OF CHECKLIST. REMOVED FROM SERVICE. REMOVED AND REPLACED GCU #1 REF Q400 AMM 24-21-06-000-801 AND 24-21-06-400-801. OPERATIONAL TEST OF THE AC VARIABLE FREQUENCY GENERATION SYSTEM GOOD REF Q400 AMM 24-21-00-710-801. RETURNED TO SERVICE.