SDR ASAA2018040824185

Service difficulty report · Cdu · Boeing 737990ER

Difficulty date: April 8, 2018
Submitted: April 24, 2018
Operation: Air carrier
Aircraft: N442AS
Make and model: Boeing 737990ER
Aircraft serial: 43293
Aircraft time: 17,396 hours, 5,785 cycles
System (JASC): 3460 · Flight Management Computing Hardware System
Part: Cdu
Part number: 1741010303
Part serial: 002881
Condition: Malfunctioned
Location: First Officer'S
Part time: 17,505 hours, 5,817 cycles
Stage of operation: NR
How discovered: O
Nature of condition: O
Precautionary procedure: O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

PILOT DESCRIBED BUZZING SOUND WHEN CLK BUTTON PRESSED ON FO FMS CDU. ACFT GROUNDED. CONFIRMED PROBLEM. SOFT BUZZING SOUND LIKE INTERNAL ELECTRICAL ARCING OCCURS FROM FO FMS CDU WHEN CLK BUTTON PRESSED. FIRST OFFICER'S NR 2 MCDU INOPERATIVE. ACCOMPLISHED SP2 BY PULLING AND COLLARING CB C1239 ON P6-1 PANEL (FMCS MCDU 2) IAW WDM 34-61-11 PAGE 3.1 REVERSED CONFIGURATION CHANGE. REMOVED & REPLACED FO'S CDU. OPS GOOD. GROUND VERIFICATION SUCCESSFUL. IAW AMM 34-61-01/401.