What was found
APU RELIABILITY COLD SOAK START UNSUCCESSFUL, 1ST ATTEMPT - SAT - 53 - FL400 MAX RPM 45% / 2ND ATTEMPT - SAT - 52 - FL400 MAX RPM 20% / 3RD ATTEMPT - SAT - 52 - FL400 MAX RPM 22%.(<P>NOTED BY MX. APU COLD SOAK CLEARED DUE TO APU INOP. </P> / <P>13JUL21 - LP 1354874 - ITEM#6 - ANC - TRANSFER TO DMI 150117, CAT B, IAW ATLAS DDG 49-11-01B, DUE 16JUL21.</P> / <P>BWI - LP 148942 ITEM 7: FOUND SHORT BETWEEN #2 THERMOCOUPLE WIRES T56 .REMOVED AND REPLACED APU WIRING HARNESS ASSY IAW WDM 49-14-11 AND SWPM 20-10-11. PERFORMED SUCESFULL APU STARTS IN GRND AND BATT POWER IAW AMM 49-11-00. PUT ACFT IN SIMULATED AIR MODE IAW AMM 32-09-02 AND PERFORMED 3 SUCCESFUL APU STARTS. PERFORMED APU BIT IAW 49-61-05, OK ON MINI FLAGS AND NO ISSUES. SEE ECM 2021P-225 FOR COMPLETE WIRING CHECKS PRIOR BETWEEN APU AND ECU AND APU FIREWALL . APU OPS CKS GOOD AT THIS TIME IAW 49-11-00. THIS CLEARS DMI 150117. MCC NOTIFIED, PLACARDS REMOVED.