What was found
DURING FLIGHT, SMELLED ELECTRICAL SMOKE IN COCKPIT. APPLIED POWER TO THE ACFT, NO ELECTRICAL ODOR NOTED. POWERED UP ACFT WITH APU & BLEED AIR ON FOR 30 MINUTES, NO ODOR NOTED. POWERED UP ACFT WITH BOTH ENGINES FOR 30 MINUTES, NO ODOR NOTED. REMOVED ALL ACFT DISPLAY UNITS DU 4 & 5 FOUND INSTRUMENT PANELS & DISPLAY UNITS COVERED IN DUST & LINT. CLEANED AWAY ALL DUST & LINT. CLEANED GLARE SHIELD FANS & INSTALLED DISPLAY UNITS. CHECKED ALL COCKPIT & GALLEY WIRING, NO DEFECTS NOTED.