As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THE COPILOTS AUDIO PANEL VOLUME COULD NOT BE CONTROLLED, DEFAULTED TO FULL VOLUME. THE MAINTENANCE TEAM DETERMINED THE CO-PILOTS AUDIO CONTROL PANEL WAS DEFECTIVE. THE AUDIO CONTROL PANEL WAS REMOVED AND REPLACED WITH A REPAIRED UNIT. OPERATIONAL CHECKS WERE SATISFACTORY AND THE AIRCRAFT WAS THEN RETURNED TO SERVICE.