What was found
DURING PREFLIGHT INSPECTION, WITH ACFT POWER ON, THE CREW REPORTED A ZAPPING SOUND FOLLOWED BY A SMALL AMOUNT OF SMOKE NEAR THE PILOT'S YOKE. MX PERSONNEL FOUND THE BULB ON THE PILOT'S CHART HOLDER (ATTACHED TO THE YOKE) SEVERELY BURNED. THE BULB WAS REPLACED AND OPS CHECKS WERE SATISFACTORY.