Installation guide

connected by external cables, to allow diagnostics to verify the serializer/deserializer interface,
transceiver, and cable. Some tests require loop back plugs.
Diagnostic tests are run at link speeds of 1-Gbps, 2-Gbps, 4-Gbps, and 8-Gbps. For information about
specific diagnostic tests, see the Fabric OS Administrator's Guide.
NOTE
Diagnostic tests might temporarily lock the transmit and receive speed of the links during diagnostic
testing. Brocade recommends that you power-cycle the switch after completing offline diagnostics tests.
Field replaceable units (FRUs)
You can replace the combined power supply/fan assemblies on site without the use of special tools.
The FRUs are keyed to ensure correct orientation during installation. Replacement instructions are
provided with all replacement units ordered.
DANGER
Remove both power cords before servicing.
DANGER
Disconnect the power cord from all power sources to completely remove power from the device.
Power supplies/fan assemblies
The two FRUs are hot-swappable. They are identical and fit into either bay. They are keyed to prevent
being inserted upside down.
Fabric OS identifies the power supplies as follows (viewing the Brocade 7800 from the nonport side):
• Power supply #1 on the right
• Power supply #2 on the left
Fabric OS identifies the fan assemblies as follows (viewing the Brocade 7800 from the nonport side):
• Fan assembly #1 on the right
• Fan assembly #2 on the left
The FRUs are cross connected so that if one power supply fails the fans will continue to run on power
from the other power supply.
Any of the following methods can be used to determine whether a FRU requires replacing:
• Check the status LED next to the On/Off switch (see LEDs on the nonport side of the Brocade 7800
on page 37).
• In DCFM, double click the 7800 switch icon to open Web Tools, then click the Power Status icon.
• Enter the psShow command at the command prompt to display power supply status.
• In DCFM, double click the 7800 switch icon to open Web Tools, then click the Fan Status icon.
• Enter the fanShow command at the command prompt.
See the Combined Power Supply and Fan Assembly Replacement Procedure for information on how to
change the FRU.
Field replaceable units (FRUs)
Brocade 7800 Extension Switch Hardware Installation Guide 39
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