The switch may be bad or more likely you need to replace the cable with a new high quality one. Mke sure you get a good connection.

@davcbr 

 

To add to @ArcherC8 check the IP addresses on the connected devices to the swith to make sure they match the scheme of the Archer C3150. If both IP addresses are different nothing will commuincate over the network. 

@davcbr Well...

I've got the thing going.   Some of my difficulty was that this is the first router that I've owned [five previously] that does not list the computers connected by cable like it does for devices connected by WiFi.  Made my diagnosis a little slow.  I'm still not sure about it, as it seems a little flakey - in Windows, I sometimes have to do a search for a computer on my network, and voila! It's found!  A simple "refresh" does nothing.  However, once it finds the compute I searched for, up pops all of them.

As far as cables...   as I said, putting back the Assus router immediately got things running.  I did try switching out a couple of cables and, I put in a Linksys switch that it seemed to like.  My suspicions lie with the C3150 however.  If I plug cables directly into the 3150, it refuses to recognize the computers that line feeds.  If I put that same  plug into the Linksys switch and cable that to the router's #1 jack, it works.  Fortunately it is an 8 port switch, so everything now goes to it.  I think the C3150 ports may be the problem.  It's working now, so I guess I'm "happy"