Precision 5820, 7820, 7920 Tower And XL Tower Are Not Able To Detect Hot-Plug Thunderbolt 3 Devices

Summary: This article describes what to do when Precision 5820, 7820, and 7920 computers fail to detect hot-plug Thunderbolt 3 devices.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
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Symptoms

Dell Precision Tower computers that are equipped with the optional Thunderbolt 3 card rev A00-A02 do not recognize hot-plug events. The hot-plug device connected to the Thunderbolt 3 card is not detected in Device Manager or BIOS.

Affected Platforms:

  • 5820 XL Tower
  • 7820 XL Tower
  • 7920 XL Tower
  • Precision 5820 Tower
  • Precision 7820 Tower
  • Precision 7920 Tower

Cause

Thunderbolt Technology Support must be enabled in the BIOS, and the device may require approval in the Thunderbolt driver.

Resolution

  1. Power on the computer and press the F2 key to enter the BIOS system setup.
  2. Click System Configuration, then select Thunderbolt Adapter Configuration.
  3. Check the box to Enable Thunderbolt Technology Support in System Configuration if it was disabled.
  4. Save the settings and reboot.
  5. If the device is not recognized, or Enable Thunderbolt Technology Support was already enabled, then go to the steps below.
Note: For any new hot-plug event, you must repeat the scan for new hardware.
  1. After you hot-plug a new device to the card, approve the device in the Thunderbolt driver. (the device is not shown in the computer and is not usable.)
  2. Right-click the Start button and open Device Manager from the start menu list.
  3. Click "Rescan for hardware changes."
  4. The device is shown and able to be used.

Affected Products

5820 XL Tower, 7820 XL Tower, 7920 XL Tower, Precision 5820 Tower, Precision 7820 Tower, Precision 7920 Tower
Article Properties
Article Number: 000134103
Article Type: Solution
Last Modified: 29 Apr 2026
Version:  9
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