The Dell Precision 5690 has Thunderbolt 4 USB-C ports that carry data, video and power, and when one stops working the cause is usually the port's mode, the cable or a driver. Test the device on each port and on another computer, and try a different cable, because a cable that carries only charging looks like a dead port.
The checks in more detail
If a Thunderbolt dock or a monitor does not appear, update the Thunderbolt firmware and the BIOS from Dell's page and check the Thunderbolt controller is listed in Device Manager. Windows' USB selective suspend can switch ports off to save power, so turn it off in Power Options, Advanced settings, USB settings. Reinstalling the USB controllers in Device Manager rebuilds the drivers. In the BIOS, check the USB configuration for Enable External USB Port and Thunderbolt settings, since an administrator may have disabled ports on a managed laptop.
A port that is loose or does not hold a plug needs repair. A power drain resets stuck ports. Thunderbolt docks pull a lot of power, and a dock that is not fully powered can make ports act up, so check the dock's own power adapter and its Thunderbolt cable, and update its firmware with the dock maker's tool. A dock with multiple monitors may also reset when the laptop sleeps, which looks like a dead port. If a Thunderbolt monitor shows no picture, test the port with a different monitor cable and an adapter to HDMI to see whether the port outputs video at all, since Thunderbolt video and data use different modes. Record which test succeeds for Dell support so they can pinpoint the failing part.
Differential
Likely causes of “Dell Precision 5690 USB or Thunderbolt device is not recognized”, and how to tell them apart
- 1
A cable without data support
What separates it The device does not appear
How to confirm Use a data cable rated for Thunderbolt or USB
- 2
USB selective suspend
What separates it Ports stop after sleep
How to confirm Turn it off in Power Options
- 3
Old Thunderbolt firmware or BIOS
What separates it A dock or monitor is not detected
How to confirm Update the BIOS and Thunderbolt firmware
- 4
A BIOS or policy setting
What separates it Ports are disabled
How to confirm F2: check USB and Thunderbolt settings, or ask IT
- 5
A damaged port
What separates it Loose or dead on every cable
How to confirm Contact Dell
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which ports fail and with which devices
- Whether the device works elsewhere
- The Thunderbolt and BIOS versions
- Whether the laptop is managed
Try in this order
0 of 8 completedTest each port and device
ReversibleUse a known-good device and cable.
Update the BIOS and Thunderbolt firmware
ReversibleFrom Dell's support page.
Turn off selective suspend
ReversiblePower Options, Advanced, USB settings.
Reinstall the USB controllers
ReversibleDevice Manager, uninstall and restart.
Check the BIOS USB settings
ReversibleF2, USB configuration.
Do a power drain
ReversibleHold power fifteen seconds.
Check the dock's power and firmware
ReversibleMake sure the dock is powered and its firmware is updated.
Test without the dock
ReversibleConnect the device directly to the laptop's port.
Model-specific
What is true of this model and not of its siblings
- Thunderbolt 4
- The ports carry data, video and power.
- Policies
- Managed laptops may lock ports.
- Dock power
- A dock needs its own supply to work properly.
- Sleep resets
- Docks may reset when the laptop sleeps.
Stop boundary
When this stops being a self-service repair
- !If every port fails after a power drain and driver reinstall, contact Dell
- !If a port is loose, it needs repair
- !Check with IT for a managed laptop
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why does my Precision 5690 USB-C port not work?+
The cable, a driver or a BIOS setting.
Are the ports Thunderbolt 4?+
Yes.
Can IT disable ports?+
On managed laptops, yes.
Will a power drain help?+
It clears stuck ports.
Why do my ports fail after sleep?+
A dock may reset, or selective suspend turned them off.
Can a dock cause USB problems?+
Yes, if underpowered.