Service difficulty report · Connector · Boeing 737990ER

Difficulty date
June 25, 2016
Submitted
June 29, 2016
Operation
Air carrier
Aircraft
N423AS
Make and model
Boeing 737990ER
Aircraft serial
35206
Aircraft time
12,768 hours, 4,133 cycles
Part
Connector
Part number
DP601
Condition
Contaminated
Location
Nr 2 Hmu
Stage of operation
IN
How discovered
O
Nature of condition
J
Precautionary procedure
K

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

What was found

WHILE ACCOMPLISHING T/C 7827300 FAULT CODE, APPEARED ON NR 2 ENGINE. THE FMV POSITION SIGNALS DISAGREE. MUST BE CORRECTED IN 50 HRS. ACFR GROUNDED. REF LOG 11622130 FOR WORK ACCOMPLISHED. INITIAL EVALUATION HAD EEC CHANNEL B HMU RESOLVER COSINE RESISTANCE AT 27K OHMS WHEN RINGING FROM EEC CONNECTOR, DP0606. REF WDM 73-25-21. REMOVED DP601 FROM HMU FOR ISOLATION AND LOST HIGH RESISTANCE. NO DEFECTS NOTED IN WIRING HARNESS NOR HMU OR EEC CONNECTORS. WHEN HMU CONNECTORS RECONNECTED, ALL RESISTANCES FOR FMV RESOLVER AND TORQUE MOTOR WERE NOMINAL. SHOOK WIRING AND ALL READINGS STAYED STEADY. ACTUATORS TEST WAS NORMAL. 3 ENGINE STARTS AND ALL INDICATIONS NORMAL. WORK ACCOMPLISHED IAW FIM 73-25, TASKS 803 AND 804.