What was found
AT FL430 WE GOT A CHECK DU5 EICAS MESSAGE. NEXT WE SMELLED SMOKE IN THE COCKPIT. REMOVED DU-870, DU-5, PN 7014300-901, SN 0412E232. INSTALLED REPAIRED DU-870, PN 7014300-901, SN 01049044. OPERATIONAL CHECKED OK, ALL WORK ACCOMPLISHED IAW MM 34-25-01.