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Serial port problems

  • Follow the suggested actions in the order in which they are listed in the Action column until the problem is solved.
  • If an action step is preceded by '(Trained technician only)', that step must be performed only by a Trained technician.
  • Go to the IBM support website at the Lenovo Support Portal to check for technical information, hints, tips, and new device drivers or to submit a request for information.
Table 1. Serial port problems and actions.

The serial port's problems and actions table with one level of row and column headers.

SymptomAction
The number of serial ports that are identified by the operating system is less than the number of installed serial ports.
  1. Make sure that:
    • Each port is assigned a unique address in the Setup utility and none of the serial ports is disabled.
    • The serial-port adapter (if one is present) is seated correctly.
  2. Reseat the serial port adapter.
  3. Replace the serial port adapter.
A serial device does not work.
  1. Make sure that:
    • The device is compatible with the server.
    • The serial port is enabled and is assigned a unique address.
    • The device is connected to the correct connector.
  2. Reseat the following components:
    1. Failing serial device
    2. Serial cable
  3. Replace the following components one at a time, in the order shown, restarting the server each time:
    1. Failing serial device
    2. Serial cable
    3. (Trained technician only) System board
The serial port might print out some messages for debugging purposes during the uEFI and pDSA configuration stages. Some external devices when attached on the serial port can cause specific device-related behaviors.
  1. In the uEFI console redirection page, disable the serial port setting to stop messages from being printed out via the serial port.