Thanks for contacting us! I am sorry this is not working as expected.
Based on your description of the behavior, our first step is to get some additional information from your system to help determine the cause of this behavior.
If you would, please keep the dock connected to the computer with monitor(s) connected to the docking station (even though one may not be working) and attach the output of our diagnostic utility PlugDebug ( http://plugable.com/support/plugdebug ) to an email to ‘email@example.com’ with the subject line ‘Ticket #384521 - Attention Pat’ as this will allow us to examine some log files from your system to help determine the next steps.
Additionally, please let me know in the email the serial number(s) from the bottom of the affected docking station(s) in the format ####A##### and the Amazon Order ID ( available from Amazon.com/orders ) in case we need to start the warranty process.