I have an Dell Inspiron 17 7000 series I purchased in Oct. 2013.  Dedicated Nvidia graphics card.  Windows 8 was preinstalled.  An update in the spring of 2014 caused my touchscreen to stop working.  I did not use my computer much and did not realize the touchscreen was not working until August.  I contacted service in September for several reasons 1.) computer would not wake up from sleep 2.) touchscreen not working 3.) sometimes the system would not shut down getting 'stuck' at black screen and lit keyboard and I would have to do a hard restart and after updating my bios nothing was resolved.  A tech came out twice, once replacing the screen unit as a whole, the frame unit around my keyboard and the underneath 'carriage' for the drive and motherboard.  It worked for a day and some other problems presented including not booting past the dell logo screen.  The tech came out and replaced my mother board,  This resolved the post frame replacement issues but the touchscreen still does not work and I have to have the computer on awake all the time because it still will not wake if it goes to sleep although I have not since had the shutdown issue.  I have done a diagnosis using Dell's online tool and all systems pass but it does not appear to test the touchscreen.  Please let me know how to message you the express tag number.  thank you in advance for your help