Users Manual

ALL
EFFECTIVITY
© Honeywell International Inc. Do not copy without express permission of Honeywell.
Page 7-1
22 Apr 2019
23-15-49
SYSTEM DESCRIPTION, INSTALLATION, AND MAINTENANCE MANUAL
ASPIRE-400
SECTION 7 – TROUBLESHOOTING
1. Aircraft Control Domain (ACD)
A. ACD Startup Functions
(1) During the SDU startup sequence, the front panel power and fault LEDs will indicate
status as follows:
(a) For regular power-up (Normal or Rapid);
(b) On initial power-up, the LEDs come up solid Green;
(c) During ACD Boot, the LEDs are set to alternately flash Red and Green and
remain flashing until the power-up cycle is complete;
(d) Power-up completion is indicated when the Power LED reverts to solid Green;
(e) A successful power sequence results in the Power LED set to solid Green and
the Fault LED unlit.
(f) Any critical failure during the power-up cycle results in the fault LED being set
RED at the point the failure occurs.
(g) Any non-critical failure during the power-up cycle results in the fault LED being
set at the end of the power-up cycle.
(2) For commanded self-test:
(a) The power LED remains solid green;
(b) The fault LED retains the previous state until results of commanded self-test
indicate otherwise.
B. ACD Boot
(1) The following drawing depicts boot stages and application dual images (Primary and
Secondary) to aid understanding of the power-on boot process performed on the SDU.
DRAFT
3rd rvw Draft as of:
29 January, 2020