Internet shutting down when disconnecting Shaw digital box

[misswoolly]

This is a strange situation and I'm hoping someone will have an idea what is going on.  In December, Telus installed PureFibre to replace the old setup.  Everything has worked perfectly since then, until this week when we decided to upgrade our tv to a newer model.  We needed to change the digital box (from Shaw) and they sent us a new box.  

So, we unplug the cable from the old box and suddenly our internet goes down completely.  We connected the new digital box but couldn't get it to work because we need an IP address and we can't get an IP address without internet.  We reconnected the old digital box to the cable and the internet came back on.  

Both the Telus and Shaw boxes on the outside of our house are close together, but I don't see how they could be affecting each other?  I'm going to have to contact Shaw and probably Telus, but I thought I would ask here just in case some wizard mind can come up with a possible cause.  I have a feeling that I will get passed back and forth between Shaw and Telus before I can get a solution.  

Thanks for reading and if you have any ideas at all, I would be so grateful to hear them.

[xray]

So you have Telus internet and Shaw TV? I didn't know that was possible. I thought Shaw only works over Shaw Internet.

I suspect you have Shaw Internet which explains what you are experiencing.

You will need to provide more information about the "box" you refer to. A model number or name would help. Your description of how things are connected is also confusing.

[misswoolly]

We have Telus internet and Shaw TV, so yes, it is possible.  Telus is PureFibre and Shaw is cable.  The box I refer to is the Shaw digital box that has to be connected to the cable and the tv.  Model DCT700, an older model that we have to update in order to use a smart tv.  As soon as we disconnect this box, our Telus internet goes down.  When we reconnect it, the internet comes back on.  As I said, I'll have to contact Shaw but I'm fairly certain I will be tossed back and forth between both companies before I get a solution.  

[xray]

Can you connect to the Telus router with a computer or phone using a browser? The URL is on the sticker on the Telus router. 

[misswoolly]

No, we are unable to connect because the internet is completely down and there is no connection when we disconnect the cable. Once we re-connect, the internet is back on.

[xray]

You don't need the Internet to connect to the Telus router. In any case, have you tried it with the Internet up? What was the URL when you did try or have have you not tried at all?

[Nighthawk]

Out of curiousity, is your Telus gateway connected to the coax in the house?