TM 5-4520-253-13
Table 3-3. Unit Maintenance Troubleshooting – Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
b. Inspect terminals (5) and potting of wires (6 and 7) to PC board.
Reconnect as needed. If
If PC board wires appear
maintenance.
spark is still not observed, replace transformer
defective, forward unit to organizational
4. HEATER BACKFIRES
Step 1. Check igniter assembly. Remove igniter from burner head. Inspect for fouling
and burned electrode (1), End of electrode must be flush with face (2) to
0.010 inch (0.254 mm) underflush.
If badly fouled or burned, replace igniter.
Step 2. Check ignition cable connector for burned spring and damaged connector.
If spring is burned or connector
damaged, replace kitted parts as
described in REMOVE/lNSTALL/
TEST/REPAIR IGNITION
TRANSFORMER AND CABLE,
page 3-110.
(8).
3-31
