Specifications

44 AT-8900, AT-9900, AT-9900s Series Switches
Software Release 3.0.2
C613-03092-00 REV C
Power LED is off If the power LED is off, it may indicate the following:
■ a loose power cord
■ a power supply failure
■ a FOM is installed in that bay
Follow these suggestions to resolve the problem:
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 If the fault LED is on, it may indicate the following:
■ there is a problem with the switch
■ the switch or management software is malfunctioning
■ a hardware fault is preventing switch startup
Follow these suggestions to resolve the problem:
1. Read the descriptions of LED flashing sequences for explanations of what
to do (see “Switch LEDs” on page 10).
2. Reset the switch. Use a small diameter pin to press the recessed reset button
on the front panel of the switch.
3. If you were attempting to download software or manage the switch over 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 software because of a faulty RS-232 terminal
port connection, you can still manage the switch by using Telnet or SNMP
until the problem is resolved.
4. Download the most current software. The Software Reference describes
how to obtain the latest software product.
Additional resources Other sources of useful troubleshooting information are:
■ www.alliedtelesyn.com
■ the Software Reference, especially the Test Facility chapter