Troubleshooting Your System 99
9
Reconnect and power on each USB device one at a time.
10
If a device causes the same problem, power down the device, replace the 
USB cable, and power up the device.
If the problem persists, replace the device.
If all troubleshooting fails, see "Getting Help" on page 119.
Troubleshooting a Serial I/O Device
1
Turn off the system and any peripheral devices connected to the 
serial port.
2
Swap the serial interface cable with another working cable, and turn on the 
system and the serial device. 
If the problem is resolved, replace the interface cable.
3
Turn off the system and the serial device, and swap the device with a 
comparable device.
4
Turn on the system and the serial device.
If the problem is resolved, replace the serial device.
If the problem persists, see "Getting Help" on page 119.
Troubleshooting a NIC
1
Run the appropriate online diagnostic test. See "Running the System 
Diagnostics" on page 111.
2
Restart the system and check for any system messages pertaining to the 
NIC controller.
3
Check the appropriate indicator on the NIC connector. See "NIC Indicator 
Codes" on page 16.
• If the link indicator does not light, check all cable connections.
• If the activity indicator does not light, the network driver files might 
be damaged or missing.
Remove and reinstall the drivers if applicable. See the NIC's 
documentation. 
book.book  Page 99  Monday, March 7, 2011  2:24 PM