Mark

Procedure to pull up fault history on a RT-910 T2CAS processor.

From ACSS Maintenance Manual 34-43-23

Self−Test Function

By momentarily pushing the TEST switch on the front panel of the TCAS Computer
Unit, maintenance personnel can display fault data for the current and preceding
flight legs. When TEST is initially activated, all annunciators (pass/fail lamps on front
of unit) are ON for a 3−second lamp test, then current fault data is displayed for 10
seconds. If no further activations of the TEST switch are made, the LRU display
cycle is terminated at the end of the 10−second fault display period, and all
annunciators are extinguished.


If during the 10−second fault display period, the TEST button is activated again, the
fault display period is aborted, a 2−second lamp test cycle is done, and the fault data
recorded for the preceding flight leg is displayed for 10 seconds. This procedure can
be repeated up to 10 times to obtain recorded data from the previous 10 flight legs.
If the TEST button is not activated again during the fault display period, the fault
display cycle is terminated at the end of the 10−second fault display period and all
annunciators are extinguished. If an attempt is made to display fault data for the
preceding flight leg when the tenth preceding flight leg fault data is displayed, all
annunciators flash for a 3−second period at a 2.5−Hz rate, after which all
annunciators are extinguished.


When less than 10 flight legs have been flown since the TCAS Computer Unit was
shop tested and recertified, less than 10 previous flight legs of recorded fault data
may be available for display. In this case, if an attempt is made to display fault data
for the preceding flight leg when the earliest flight leg is displayed, all annunciators
flash for 3 seconds at a 2.5−Hz rate and then all annunciators are extinguished.
The TCAS PASS and TCAS FAIL annunciators indicate the status of the TCAS
Computer Unit only. All other annunciators reflect the condition of the respective
sub−system. During troubleshooting, the TCAS Computer should not be removed if
the TCAS PASS lamp is on.

(The "RA DISP" fault in this video was caused by the Inertial Reference Systems not being aligned.)