Applicable To
- UD-CA1A
If an external monitor doesn't receive a signal when connected to the HDMI port on the UD-CA1A, the issue is usually related to the host computer's USB-C video capabilities, the USB-C cable, or the display connection.
The UD-CA1A uses USB-C Alternate Mode for video output. It does not use DisplayLink and does not require a separate video driver.
Troubleshooting Steps
- Confirm that the host computer supports video over USB-C.
Not all USB-C ports support video output. The USB-C port used with the UD-CA1A must support Alt Mode, or be a compatible Thunderbolt 3, Thunderbolt 4, or USB4 port that supports video output.
Check the computer manufacturer's specifications or user manual to confirm the USB-C port's capabilities.
If the USB-C port supports only USB data or charging and not video output, HDMI video through the UD-CA1A will not work.
- Use the original USB-C cable included with the UD-CA1A.
The USB-C cable connecting the dock to the computer must support Alt Mode video.
Many USB-C cables intended primarily for charging, or cables limited to USB 2.0 data, do not support video even though the connectors are physically compatible.
Always test with the original USB-C cable included with the UD-CA1A first.
- Confirm the monitor is using the correct HDMI input.
Manually select the HDMI input connected to the UD-CA1A using the monitor's controls. Some monitors do not automatically switch to an active input.
- Use a direct HDMI connection.
Connect the UD-CA1A directly to the monitor using an HDMI cable.
When troubleshooting, avoid HDMI splitters, converters, adapters, or other devices between the dock and display.
- Confirm the display configuration.
The UD-CA1A supports one external display through its HDMI output. It does not provide multiple independent external display outputs.
- Power cycle the dock.
Disconnect the USB-C cable from the computer.
Disconnect the power adapter from the UD-CA1A.
Wait approximately 30 seconds.
Reconnect the power adapter to the dock.
Reconnect the USB-C cable between the UD-CA1A and the computer.
Expected Result
The connected monitor should be detected and display video through the UD-CA1A HDMI output.
If the Issue Persists
If HDMI video still isn't working after completing the steps above, you may need additional diagnostics.
Download and run PlugDebug with the UD-CA1A connected: https://plugable.com/pages/plugdebug
Email the resulting ZIP file to support@plugable.com and include a brief description of the issue and the troubleshooting steps you have already completed.
