What was found
FLIGHT 3556, DURING CRUISE, FIRST OFFICER’S YOKE CHART LIGHT PRODUCE SEVERAL LARGE SPARKS. SWITCH WAS IN OFF AT TIME OF INCIDENT. ATTEMPTED TO ISOLATE POWER WITH HELP OF MAINTENANCE BUT WERE UNABLE TO. CIRCUIT BREAKER G6 POPPED. NOTICED CHART TRAY SHOWED SIGNS OF CHARING AND A SMOKE ODOR EMANATED FROM AREA. ELECTED TO DIVERT. AIRCRAFT LANDED WITHOUT INCIDENT. AIRCRAFT WA REMOVED FROM SERVICE. FOUND WIRES BEHIND CHART HOLDER BROKEN, REPAIRED WIRES TEF J001-22 AND TEF J002-22 IAW ESPM 20-33-00 AND ETN-CR-20-010. OPS TESTED GOOD IAW AMM 33-13-07. AIRCRAFT RETURNED TO SERVICE.