As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. RIGHT AFTER ROTATION STRONG PLASTIC ELECTRICAL SMELL NOTICED BOTH BY CABIN CREW & COCKPIT CREW. APPLIED SMOKE QUICK ACTION AND SMELL DISSIPATED. EMERGENCY WAS DECLARED FOR LANDING AT PHL. ACCOMPLISHED J/C 26L00021001 & FOUND ELECTRICAL ODOR COMING FROM SIDEWALL BALLAST ABOVE SEAT 4A. REMOVED AND REPLACED SIDEWALL BALLAST, IAW AMM 33-21-11.