Allied Telesis AT-GS924MX Installation Manual page 114

Chapter 7: Troubleshooting
114
is carried on pins 4, 5, 7, and 8 on the RJ-45 port, the same pins
that carry the network traffic. The other mode, Alternative A,
defines pins 1, 2, 3, and 6 as the power carriers. The
AT-GS924MPX and AT-GS948MPX Switches do not support
Alternative A. Most powered devices are designed to accept power
by either mode, but some legacy devices may only support one
mode. This can be verified by reviewing the device's
documentation or data sheet. Legacy devices that only support
Alternative A will not work with the switches.
Check that the device's power requirements do not exceed 30 W.
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This can be verified by reviewing the device's documentation or
data sheet.
Verify that you are using the appropriate category of twisted-pair

cable by referring to Table 1 on page 26.
Use the management software on the switch to determine whether
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PoE is enabled on the port. The default setting for PoE is enabled.
Use the management software on the switch to determine whether
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the PoE power setting for the port has been reduced to a value
below the power requirements of the device.
Try connecting the device to a different port on the switch.
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