WAVEJET MICROWAVE OVEN
COMPONENT MAINTENANCE MANUAL
WITH ILLUSTRATED PARTS LIST
25-30-43
Page
103
March 15, 2003
3.
Troubleshooting
A. The following troubleshooting guide lists common potential faults that may
occur in this equipment.
NOTE:
All wiring connections have been verified and all terminal board
connections are tight.
B.
For any recurring or unlisted fault conditions, call TIA directly for technical
assistance.
C.
Perform Fault Isolation Procedures
If the unit fails the normal operational functional tests, proceed to check out
the various test points as described in the following tables. This will localize
major defects. The readings given are for a normal unit operating within
specification. During the functional test, the failure mode or problem may
become known. To determine the location of the specific defective
components, a methodical troubleshooting approach should be
implemented. A probable cause of failure chart and fault isolation chart is
provided. The first step is to evaluate the UUT (Unit Under Test) by
referring to the probable cause of failure chart.
Probable Cause of Failure Chart
Symptom
Fault Isolation
The display (numbers) are not illuminated.
A. No or low input voltage. Measure
input voltage. Voltage should be 28
Volts DC.
B. Check load shed circuit on aircraft.
C. Check load shed fuse in microwave.
(P/N 400-1860-01 only)
D. Noise filter failure. Check noise
filter.
E. Controller card failure.
F. Check liner overheat thermostat.
Display is active, controls are
unresponsive.
A.
Check switch panel overlay for
failure.
B.
Check controller card for failure.
Display is active, +/- respond, but will not
count down when “Start” is pressed.
Inside lamps stay on.
Check all door interlock switches. One or
more may be stuck open or need
adjustment.