Issue with internet modems and working properly

I have a friend who came back from vacation to find his internet not working.
His neighbors said there was a lightening storm while he was gone, and could possibly be a lightning strike.

He got a new internet company to come out and hook up all the new lines. He went out and bought new modems/routers for the whole house.

Problem is now, when he hooks up one new modem/router in one room, the others in the other rooms stop working. He's switched them back and forth and all around. He had them all tested to make sure that they all work correctly too. And it still happens, that if one is working fine in one room, the others won't work.

The cable company says there is nothing they can find wrong on their end.

Curious as to what this could be the result of.

Any guesses?

 

Ah, yes........I think I remember I used to have a splitter on my one modem/router for separate computers. I think he's doing it without a splitter and thinking it's all modems/routers.

I will tell him what you said. Thanks!

 

A splitter on a modem won't work either. (tried that last year when my router died) Only 1 computer will be seen and usable. A router is needed to get more than 1 device onto the internet.

 

Well, I had a splitter on my modem/router and was able to hook up as many pc's as the splitter would allow, until I moved and had to get a different internet company service. They said their system didn't allow splitters to be used....you have to get a separate service for each pc. Rip off anyone?

I told my friend that things may have changed because he got the same internet company now that I've had for a few years.....and they don't "do" splitters. So he may be SOL.

 

Define what you mean by "splitter". Normally, a single cable run comes into a residential building, is connected to a modem which is connected to a router. The modem and router may be combined into one unit, though it is typically preferable to have them separate.
Often the router combines a wireless part (providing Wi-Fi) with a wired part, which may have a built-in switch allowing multiple wired connections. You can add additional switches to provide for additional wired connections. These switches can be considered "splitters", in a sense. They allow you to provide multiple connections from a single feed, but they are Ethernet, not cable (as in cable TV or cable Internet), connections. They are what will plug into your computer.
Multiple modems should not be used, multiple routers are normally not needed and should be avoided unless you know what you are doing and have a specific reason.