Unsolved
1 Rookie
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2 Posts
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17
July 3rd, 2025 12:39
Dell laptops do not do single USB-C cable portable monitors
I'm having a problem with my Lattitude 3450 and my Precision 3490. My external USB-C monitor gets power from the laptop but no video when USB-C cable is used. If I plug in an external power source to the portable monitor it works. If I plug in BOTH a USB-C cable AND an hdmi cable to the laptop sends video via hdmi and power via usb-c. It's like the USB-C port can only provide video OR power but not both on a single USB-C cable.
My portable monitor works as expected using an older Surface Tablet (single USB-C cable for power and video) as well as with a Samsung cell phone. (only other things I have to test with)
I have tried:
- Updated BIOS
- Updated Dell Intel Xe Drivers
- Turned brightness down on monitor to lowest setting
- tried to find any power settings in BIOS (none to do with USB-C)
PS. I forgot to mention it is a no-name 15 inch 1080p external monitor.
ejn63
10 Elder
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28.6K Posts
1
July 3rd, 2025 13:14
How much power does the monitor need? If it's more than 15W, you will need an additional power connector.
Shinare
1 Rookie
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2 Posts
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July 3rd, 2025 13:30
It powers it just fine from the USB-C port as long as you also plug in an HDMI cable to provide video. Trying to do both with a single cable only provides power to the monitor, no video.
Like I said, it works with a single USB-C cable on my 5 year old Surface Tablet and my Samsung S20 FE. Its only these Dell laptops I have that require both power and video cables.