RE: CSV-5300 with the Surface Pro 3

My surface pro 3 / MST CSV-5300 set up with 1 HDMI and 2 DVI screens and docking station which has been working OK since 19th Dec has suddenly started having a similar problem following a wake from sleep in the dock.  I now cant get it to drive 3 screens at all ( the best is 1 DVI screen not the HDMI) whether dock connected or plugged directly into the Surface despite reboots in or out of the dock. I have checked the screens and cables individually.  Any suggestions or am I going to have to return the MST under warranty?