If it’s a SWITCH it ain’t gonna work. Period.
Obviously, one would never hear about good-working router issues...they just do what they are supposed to do. But, I bot a brand-new Linksys BEFSR41 at a church sale for $4! Sealed in plastic-wrap! It worked for about a day or two, then I plugged my laptop into it and it just stopped. I did every variation of power-down, reset, reboot, etc etc I could think of, before bypassing said router and visiting several user groups. There were oodles of comments from folks (clearly much more skilled than I am) who could not get the thing to work. Many appeared to have had good luck with older ones, then theirs crapped out, then they bot a new one of the same type and couldn’t get it to work. That’s all I can tell you.
My latest guess -- the link from the switch to the cable modem is not working, due to the wrong kind of ethernet cable. Plugging that cable into a different port on the switch might help.
But I still need to figure out what kind (model number) of switch she has. I'm not having much luck there yet.
Maybe that is why it cost $25.00! Tomorrow I will take the switch back & replace it with a router. We have had a Linksys router for eight years and have never had a problem.