As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A/C RETURNED TO STAND DUE TO ACRID BURNING ODOR AND SMOKE IN FLT DECK AFTER SECOND ENG START. CABIN CREW AT L1 ALSO REPORTED STRONG ODOR AND HEARD A NOISE FROM THE FWD E/E BAY BELOW HER JUMP SEAT. P110 PANEL SHOWED BURN MARKS, MONITOR CARD M24518 BURNED. TERMINAL BLOCK ATTACHED TO ABOVE ALSO BURNED. SHORT LENGTH OF WIRES BURNED AND BLACKENING OF WIRES NEARBY NOTED.