Specifications

Hardware Reference 43
C613-03084-00 REV A
Note If the port is disabled, someone has used the software to manually disable
it. You should find out why the port was disabled before you enable it.
Power LED is off
This can indicate:
■ A loose power cord.
■ A power supply failure.
■ A FOM is installed in that bay.
Perform these steps in sequence:
1. Check that the power cord connections are secure.
2. Check that all switches and circuit protection devices are in the ON position.
3. Ensure that the supply voltage is within the operational range.
• AC models: 100 V to 240 V AC, 47 Hz to 63 Hz
• DC models: 40 V to 60 V DC
Fault LED is on
This can indicate:
■ There is a problem with the switch.
■ The switch or management software is malfunctioning.
■ A hardware fault is preventing switch start-up.
Perform these steps in sequence:
1. Check “LEDs and What They Mean” on page 23 for descriptions and
explanations of LED flashing sequences.
2. Reset the switch. Use a small diameter pin to operate the recessed Reset
button on the switch’s front panel.
3. If you were attempting to download software or manage the switch via the
RS-232 Terminal Port, check that connections between the Terminal Port
and local terminal or PC are secure.
If you cannot access the switch’s software because of a faulty RS-232
Terminal Port connection, you can still manage the switch via Telnet or
SNMP until the problem is fixed.
4. Download the latest software release. How to obtain the latest software
release is described in the AT-9900 Series Software Reference.