As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 7000 FT CLIMB EPR 250 - CLIMBING CLEAN HEARD LOUD BOOM WITH A/C SHUDDER ONCE. ALL ENG IND NORM AND STEADY. PNEU NORM. NO VISIBLE DAMAGE FROM CABIN F/A'S. ATB CVG UNEVENTFUL. DECLARED EMERGENCY WITH CVG DEPT CONTROL. BORO BOTH ENGINES, OK. FOUND LEFT ENGINE ANTI-ICE VLV LIGHT FLICKERING AT POWER. REPLACED ANTI-ICE VLV, OPS CHECKS OK.