Technical Support FAQs

Mac OS cannot detect my new PCI or PCIe expansion card. What do I do?

To determine if Mac OS detects your expansion card, you need to check System Information to see if the card is listed under the appropriate heading or is listed with an error (for example, Device has not been configured). An example of an appropriate heading for a network card is Ethernet Cards. The expansion card is listed in System Information as the name of the chipset. You can find the name of the chipset on the Technical Specifications tab for the product ID on

To open System Information, complete the following:

  1. In the upper-left screen, click the Apple icon.
  2. Click About This Mac.
  3. Click More Info or System Report.

If you installed a new PCI or PCI Express expansion card and Mac OS cannot detect the card, you can complete the following troubleshooting tasks to help to resolve the issue:

  • Turn off the computer, unplug the power cord, and remove the expansion card. Put the card back into the computer, making sure to apply firm pressure across the entire card. If the card is on an angle, it can cause issues and may not function properly.
  • Move the expansion card to another PCI or PCI Express slot.

Note: PCI Express cards work in PCI Express slots that are longer than the card and do not use the entire slot's capabilities. PCI Express expansion cards do not fit or work in PCI expansion slots, and PCI expansion cards do not fit or work in PCI Express expansion slots.

  • Put a different expansion card in the slot that is experiencing the issue.
  • Put the new expansion card in another computer.

If you completed the previous steps and determined that the problem is not with the card or expansion slots on the motherboard, you may need to update the EFI firmware on your system.

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