As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WALKED ONTO ACFT, BATTERY SWITCH WAS ON. COCKPIT SMELLED OF ELECTRONICS OVERHEATING AND RED DISPLAY MESSAGE SAYING " DISPLAY TEMP" ON ED1 AND ED2 ILLUMINATED. IMMEDIATELY SHUT BATTERY OFF. R & R EFD3 AND EFD4 IAW AMM 31-61-01. OPS CK GOOD.