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Question

SB8200 Causing interference with cable TV

  • 19 January 2023
  • 2 replies
  • 141 views

I Installed a new SB8200 on my network today.  Everything is fine with the internet.  It’s nice and fast.  However, I have 3 cable boxes.  We’re not talking smart TVs.  It’s cable boxes connected with coax.  The picture on all 3 is super choppy and pixelated ever since installing the cable modem.

 

Seems like there should be no connection, since the TVs are not reliant on the internet for their programming.  However, I did some testing.  The second I turn off the SB8200, the cable picture clears up.  As soon as I plug the modem back in, the picture on all 3 pixelates again.  There is no question that the cable modem is causing interference on my cable TV picture.

is there any way to fix this?  Other than returning my new modem and putting my old modem back in play? 

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2 replies

S
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Hello igendreau

                           Thanks for the detailed explanation, since you have done with all possible trouble shooting already we would suggest you to try factory reset on SB8200 and check whether the configuration matches. cable modems are designed only for internet use and since the configuration of the modem and TV are not matching it causing the interference, so we would suggest you to check with Internet service provider to have a look on the setup directly by taking tech visit and they will isolate the issue and resolve it.

SURFboard Community Moderator Team
plemans
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Userlevel 6
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at some point you have some splitters. 

Make sure the coax coming into the house goes directly to a double splitter. One leg from that should go directly to the modem. And the other should go to feed the cable boxes (with separate splitters). 

Also check to ensure the splitters are setup properly (coax going to the in and then out to devices). If wired right,  the SB8200 shouldn’t be sending any feedback to the other devices. That’s where I’d start. 

 

Current setup: Netgear CM3000-->Netgear RBE973S-->2.5gig tp-link switch, Xfinity 2.4gig/350mbps
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