SDR UALA2011121406840

Service difficulty report · Relay · Boeing 777222

Difficulty date: December 13, 2011
Submitted: January 13, 2012
Operation: Air carrier
Aircraft: N210UA
Make and model: Boeing 777222
Aircraft serial: 30216
Aircraft time: 42,265 hours, 9,251 cycles
Engine: Pwa PW4077
System (JASC): 2430 · DC Generating System
Part: Relay
Condition: Faulty
Location: Dc Power System
Stage of operation: IN
How discovered: 9
Nature of condition: O
Precautionary procedure: K

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

What was found

DC POWER WILL NOT ENERGIZE WHEN BATTERY SWITCH PUSHED IN. RELAY K24006 & K24025 REPLACED AT P310 POWER MANAGEMENT PANEL, NO HELP. NOTE, GROUND POWER ENERGIZED & BATTERY SWITCH ON, DC POWER ENERGIZED, DE-ENERGIZED GROUND POWER , DC POWER STAY ON. BATTERY SWITCH OFF, DC POWER DE-ENERGIZED & PUSH BATTERY SWITCH ON, NO DC POWER. NO APU FIRE TEST OR UNABLE TO START APU. REPLACED DIODE BLOCK TB404 18F,D,B REF WDM 24-09-26. ACCOMPLISHED MAIN BATTERY TEST REF MM 24-31-01 AND STANDBY SYSTEM TEST, ALL NORMAL.