USB-C DP alt mode / Thunderbolt not working

[PawelFlyer]

Hello,

Unfortunately, I spilled some tea on my notebook. I immediately opened it, disconnected the battery, and left it to dry for a few hours. When I turned on my PC, I couldn't get a video signal to my monitor connected by a USB-C cable. I tested the USB-C port with an SD card reader, and I am getting only USB 2.0 speeds, so evidently, there is something wrong with USB3 / Thunderbolt data lines. I ran the UEFI HP diagnostics tool, but all USB and Thunderbolt tests passed OK. I tried to clean the port and did the reset procedure (press 30s power button with the battery disconnected).

I can charge the notebook with this port and use it as a USB 2.0 port.

Do you think there is any chance of fixing this?

[Hawks_Eye · Accepted solution]

Hi @PawelFlyer 

Welcome to the HP Support Community!

Thanks for posting your query! We're here to help you get back up and running.

It sounds like the liquid spill may have affected the high-speed data lines of your USB-C port while leaving power delivery and basic USB 2.0 functionality intact.

Since the UEFI diagnostics passed, the issue is likely physical damage rather than a software or firmware problem.

Possible Fixes to Try

Check for Bent or Corroded Pins

• Use a flashlight to inspect the USB-C port for bent pins or corrosion.
• If you see residue, gently clean it with isopropyl alcohol (90% or higher) and a soft brush.

Reinstall USB & Thunderbolt Drivers

• Open Device Manager (Win + X → **Device Manager`).
• Expand Universal Serial Bus controllers and Thunderbolt (if listed).
• Right-click each USB-related entry → Uninstall device → Restart your laptop.
• Windows should reinstall the drivers automatically.

Check BIOS & Firmware Updates

• Visit HP’s support page for your model and check for BIOS updates or Thunderbolt firmware.
• If an update is available, install it carefully.

Test with Another USB-C Device

• Try connecting a different USB-C monitor or accessory to confirm if the issue is specific to certain devices.

Consider a USB-C Hub or Dock

• Some users have found that using a powered USB-C hub restores full functionality, bypassing damaged data lines.

If the Issue Persists

• Since charging works but high-speed data doesn’t, the USB-C controller or physical traces on the motherboard may be damaged.
• If cleaning and driver updates don’t help, a motherboard repair or replacement might be needed.

If you want to avoid motherboard replacement, a USB-C to HDMI adapter or external dock might be a workaround for video output. 

Let me know what happens at each step!

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Take care, and have an amazing day!

Regards, 

Hawks_Eye