media disconnected

when   I boot the  computer with ethernet  i geta  round what looks likea basket ball and saw no connection it does eventually go to it  but take over 5minutes it is like something is  blocking it. said media disconnected. I have tried all the trouble shooting  and have had several techs try and fix the issue. I am using windows 10 and have the new 2004 update' it like my home  connection does not  work. have tried the  modem reset had    the signal  ooted and still the same thing.  One of your techs said it  is the cord which i find hard to believe. not sure if it is my computer of if it i  something with  comcast. But it sure would be nice to have it  fixed