Service difficulty report · Starter Gen · Boeing 737724

Difficulty date
September 17, 2025
Submitted
September 19, 2025
Operation
Air carrier
Aircraft
N17753
Make and model
Boeing 737724
Aircraft serial
30463
Aircraft time
69,782 hours, 27,186 cycles
Part
Starter Gen
Part number
28B5459
Part serial
24A1472
Condition
Faulted
Location
Apu
Part time
18,723 hours, 7,568 cycles
Stage of operation
IN
How discovered
V
Nature of condition
B
Precautionary procedure
K

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

What was found

APU DROPPED OFF LINE PUT THE GENERATORS OFF, BACK ON, THE APU BUSS STRONG SMOKE ODOR. R & R APU STARTER/GENERATOR IAW AMM TASK 49-41-21-400-801 UP TO STEP H,7. FOUND TERMINAL LUGS FOR WIRING HARNESS WITH BURN DAMAGE. ON INSPECTION OF TERMINAL LUGS, FEEDER CABLE DAMAGE FOUND, DAMAGE GOES THROUGH FIREWALL FEED THROUGH IN JACK SCREW COMPARTMENT. CLEANED APU STARTER/GEN ELECTRICAL CABLES, FOUND NO DAMAGE TO CONDUCTORS, JACKET INSULATION, OR TERMINAL LUGS ON WIRES W4722-0001, 0002, 0003, 0004. WIRE 0001 HAS BEEN IDENTIFIED WITH A MARKER 1 AND A RED SHRINK TUBE BAND. WIRE 0002 HAS BEEN IDENTIFIED WITH A MARKER 2 AND A YELLOW TAPE BAND. WIRE 0003 HAS BEEN IDENTIFIED WITH A MARKER 3 AND A BLUE SHRINK TUBE BAND. VERIFIED RESISTANCE BETWEEN WIRE CONDUCTOR AND TERMINAL LUG AT LESS THAN 0.02 OHMS. REF WDM24-21-31-1. ISOLATED APU STARTER/GEN FEEDER WIRES BY REMOVAL OF M1710, APU START CONVERTER UNIT, REF MM49-41-61-00INSTALLED BACK IN ACFT E&E RACKS.