Troubleshooting Your System 1534 Reconnect and power on each USB device one at a time.5 If a device causes the same problem, power down the device, replace theUSB cable, and power up the device.If the problem persists, replace the device.If all troubleshooting fails, see "Getting Help" on page 185.Troubleshooting a Serial I/O Device1 Turn off the system and any peripheral devices connected to the serialport.2 Swap the serial interface cable with a cable in good condition, and turn onthe 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 acomparable 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 185.Troubleshooting a NIC1 Run the appropriate online diagnostic test. See "Using Online Diagnostics"on page 171.2 Restart the system and check for any system messages pertaining to theNIC controller.3 Check the appropriate indicator on the NIC connector. See "NIC IndicatorCodes" on page 20.• If the link indicator does not light, check all cable connections.• If the activity indicator does not light, the network driver files mightbe damaged or missing.Remove and reinstall the drivers if applicable. See the NIC'sdocumentation.