Can't connect to internet see below

I have a xps 8700 came with 8.0 upgraded to 8.1 then 10.  Was going ok until 8/23 when the computer wouldn't boot up.  Took to tech (out of warranty) got back to day 8/28 NOW the desktop won't connect to the internet via fiber optic cable.  My hp laptop is on the same cable and working fine.  It is on 10, I have a trouble ticket in to internet service in case it IS the net but I don't think so looked inside the puter could not see any obvious problems.  The tech cleaned the puter of dust and software issues.  I am hoping the fix is simple.