What was found
ON DEPARTURE, PASSING FL190, SPARKS CAME OUT OF OVERHEAD CIRCUIT BREAKER PANEL. THERE WAS NO SMOKE OR FUMES. LOST LT PFD & MFD, LT FMC, LT GPS. DECLARED AN EMERGENCY & RETURNED TO OUR DEPARTURE. AFTER CREW DEBRIEF FOUND 4 C/B'S POPPED. P6-3 CAPT PRIM INSTR BUSS OD 5AMP. P6-3 115 VAC BUS L XFR 20AMP. P5 ALT BUS B 5AMP. P5 AURAL WARN SPKR RT 2.5 AMP. ALSO RECEIVED EICAS MSG CABIN ALT AUTO 1&2, COMPARATOR BITE, LT ENG PROBE HEAT, & CAPT INST XFR. FOUND MAIN CARGO SMOKE DETECTION PANEL D09207 CONNECTOR BACKSHELL SHORTED TO WIRE BUNDLE. WIRE W2358-0067-22 REPAIRED, WIRE W2066-0315-20 REPAIRED, REPAIRED WIRES W2344-0007-12, W2344-0008-12, W2344-0009-12, W2344-0010-18. SYS TESTED GOOD.