Certain Ports are not functional when docked with Precision 7520/7720 UMA Graphics config

Issue

It may happen that some of ports on a Docking station do not work when docking with Precision 7520/7720.  This occurs because of a design limitation of the system if the integrated graphics is used. This only occurs on System with UMA Graphics without a discrete Graphics Option.

The Label on the bottom cover illustrated the Ports that will not work with integrated graphics only configuration.

Solution

Try to only use the Ports not marked on the above picture.

As a workaround, you should use Dell USB Type-C Docks like WD15 and TB16.