Honeywell CIU 888 Troubleshooting And Maintenance Manual page 42

FIGURE 3-2
FIGURE 3-3
3 - 2
Hardware Troubleshooting
e) Replace a defective power supply module or have it replaced.
6. Check the power LEDs of the carrier board:
a) Check the start-up sequence. The correct start-up sequence is as
follows:
i. The first two LEDs (12 Volts and 5 Volts) light up (see
FIGURE 3-2).
CIU 888: First two power LEDs of carrier board light up
ii. The COM express module starts.
iii. All six LEDs light up (see FIGURE 3-3).
CIU 888: All six power LEDs of carrier board light up
b) If no LEDs light up, check if the cable between the power supply
module and the carrier board is securely connected. Also check
the cable for any signs of damage. Replace a defective cable or
have it replaced.
c) If the first two LEDs light up but subsequently the COM express
module does not start, perform a power cycle by switching the
CIU 888 off and back on.
Troubleshooting & Maintenance Guide
CIU 888
Part No.: 4417594_Rev11