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"POST error-1804:Unauthorized network card is plugged in..." appears on screen even if correct card or no card is installed- ThinkPad Edge

"Post error,1804:Unauthorized network card is plugged in...." appears on the screen at the end of POST and you may not be able to enter BIOS setup. This occurs when your system is below BIOS level 80ET26WW.


Affected configurations
  • ThinkPad Edge 14 and Edge 15
  • ThinkPad Edge E40 and Edge E50



The CMOS data may become corrupted under certain circumstances, such as RTC (CMOS) battery has no power or using some tool to write CMOS data, etc.

Following these steps to clear and prevent this post error.

Step A). To clear this 1804 POST error:

  1. Remove AC adapter, main battery, and RTC (CMOS) battery.
  2. Reconnect AC adapter and RTC battery,and Power on your system.
  3. Enter Setup by pressing F1 during POST, then pressing F9 key to load default settings.
  4. Select F10 Key to Save settings and exit BIOS, then restart;

Step B). Update to BIOS 80ET30WW or higher to prevent this 1804 POST error on the system in the future.

If you are unable to find what you are looking for, please do try the following options:
1. Lenovo Assisted Search
2. Product usage and general troubleshooting tips
3. Lenovo Support Forum
4. Technical Support Call Centre

Country Availability
Document ID : HT004880
Legacy Document ID : MIGR-75741
Last Updated :
Copyright © Lenovo 2013, all rights reserved
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