As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - FLT 3525 - DURING PREFLIGHT, CREW NOTED A STRONG SMELL OF BURNING WIRE OR INSULATION. MAINTENANCE FOUND A BAD LIGHT BALLAST AT LOCATION 22. BALLAST WAS REMOVED AND REPLACED IAW SAAB MM. OPERATIONAL CHECK WAS GOOD AND AIRCRAFT WAS RETURNED TO SERVICE. (M)