Error Message when Connecting to a WD19 Dock with a Dell Speakerphone with Multiport Adapter (MH3021P)

Summary: The following article provides information about why the High-Definition Multi-Media Interface (HDMI) port on your dock is not working. An error message is shown on-screen when connecting the MH3021P Speakerphone to the WD19 dock. ...

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Symptoms

Note: Dell has renamed the Dell Mobile Adapter Speakerphone - MH3021P, to the Speakerphone with Multiport Adapter - MH3021P.

Dell Speakerphone with Multiport Adapter (MH3021P) owners may report an on-screen error message

The HDMI port on your dock will not function when the adjacent DisplayPort over
USB-C is being utilized for video.

Press F1 key to retry boot.
Press F2 key for setup utility.
Press F5 key to run onboard diagnostics.

The Error message is shown during the Power-On Self-Test (POST) stage of the laptop starting up.

The error occurs when you connect the hardware in this order:

  1. Connect the AC adapter to a Dell WD19 series docking station.

  2. Connect an external monitor to the HDMI port (See Port 8) of the WD19 series docking station and turn on the monitor.

  3. Connect a MH3021P Speakerphone to the USB Type-C port (See Port 9) next to the HDMI port on the rear of the dock.

    WD19 Series Rear Ports

  4. The WD19 series dock is then connected to the laptop.

  5. The laptop is turned on and shows the error message during POST.

Cause

The HDMI and Multi-function DisplayPort (MFDP) USB Type-C ports on the back of the docks in the WD19 family are mux.

HDMI and MFDP ports on the rear of the WD19 series dock

Resolution

Note: The laptop, dock, external monitor, and speakerphone are all working as designed. There are no hardware issues here.

 

This is the Expected Behavior of a Dell laptop connected to WD19 Series Dell Docking Station with these peripherals.

You must connect the MH3021P Speakerphone directly to your device. Do Not connect it through the docking station.

 

Affected Products

Dell Speakerphone with Multiport Adapter – MH3021P, Dell Dock WD19, Dell Performance Dock - WD19DC, Dell Performance Dock – WD19DCS, Dell Dock – WD19S, Dell Thunderbolt Dock - WD19TB, Dell Thunderbolt Dock – WD19TBS
Article Properties
Article Number: 000184150
Article Type: Solution
Last Modified: 08 May 2026
Version:  6
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