Could Dish Signal be interfering with my Cable Modem?

[Steve Mackay]

So I've been having problems with my cabel internet service from Comcast recently. The comcast guy comes out on Sunday and basically is fuming at the dish network people screwing up the cable modem.

I basically have cable TV, Dishnetwork (DVR 522) and a cable internet running in the house. I'll try and explain as best as I know how it is connected. First off the cable signal is split in two. One of those feeds goes directly to the cable modem to make it as strong and clean as possible.

The other (I believe) get's diplexed (perhaps twice????) with the two signals from the satellite dish and put through the house system. It get's undiplixed at the back of the 522. Then the output for the second receiver for the 522 has it's own line run directly up to the bedroom TV.

I'm not sure I got that right but the basics are there. So the comcast guy tells me that the LNB is backfeeding a voltage to the cable modem that is frying the modem. He is going to charge me a $69 service call charge and charge me for replacing the modem.

THe funny thing is that I had my cabel modem installed in September 05 and I had my Dishnetwork installed October 05. It's been working all this time. The comcast guy explained that the back voltage from the Dishnetwork system over time has been slowly frying the modem. You're only seeing the results today.

Does this make sense?

 

[goaliebob99]

Nope.. It cant happen as the antenna line/side of the dilexor cant pass power like how the sat side can.

1. Is your cable system grounded? to NEC regs

2. Is your sat system grounded to NEC regs?

Im willing to bet that the cable system isnt and that could be the cause of the problem. Also there could be frey in the wire somewher causing what your seeing on the cable modem line.

 

[Steve Mackay]

Not sure if grounded - look where?

Where would the cable and satellite system be grounded? I assume you are meaning the shielding of the RG6 needs to be grounded through the connector somehow? Where should I look?

I'm pretty sure something is happening to the modem. The cable guy says we are getting a great signal. In the last 4 weeks this is the 3rd modem that we have gotten. After each new modem it works for a while then nothing. The latest was installed yesterday and everything seemed to be working fine for a couple of hours. Then the modem stopped working. It's not easy for me to tell if it is the signal or the cable modem but I assume it is the modem based on what the cable guy was saying.

 

[Steve Mackay]

Could water/ice in junction box be problem?

With the constant opening and closing of the junction box by the service companies it has gotten cracked and I'm not sure if it is water tight anymore.

This was another complaint of the Comcast guy, that the dish network guys stuffed all their connection in the Comcast connection box and eventually broke the box.

 

[Van]

Sounds like your cable guys are doing alot of finger pointing at dish, I would call dish and have them come out to inspect theyr system and tryto seperate it from your cable service so that way comcast wont have anything to point at and blame, besides dish isnt supposed to use the comcast lines that are active anyways.

As for the grounding you will have to follow the comcast line from where it ataches to the house down to the box and look for a silver or brass looking bar that has a coax splice built into it that the coax is atached to. There will be a wire atached to this that will go to either a house ground, a cold water pipe, or a meter or fuse box, if not outside check in the basement and if there isnt anything like this then its not grounded, the same goes for your dishnetwork system and it needs to be corrected.

 

[dishguy15022]

i don't see how our dish system could be affecting your cable modem. I think it is an issue with your cable modem. Is your cable modem plugged into an electrical outlet or a power strip? maybe you should check the voltage from the electrical outlet. I have been to a couple service calls where the electrical outlet was switched around and eventually burned out the receivers.


yeah, check your ground to the dishnetwork system and check where your cable is grounded.

 

[sksatellite]

So I've been having problems with my cabel internet service from Comcast recently. The comcast guy comes out on Sunday and basically is fuming at the dish network people screwing up the cable modem.

I basically have cable TV, Dishnetwork (DVR 522) and a cable internet running in the house. I'll try and explain as best as I know how it is connected. First off the cable signal is split in two. One of those feeds goes directly to the cable modem to make it as strong and clean as possible.

The other (I believe) get's diplexed (perhaps twice????) with the two signals from the satellite dish and put through the house system. It get's undiplixed at the back of the 522. Then the output for the second receiver for the 522 has it's own line run directly up to the bedroom TV.

I'm not sure I got that right but the basics are there. So the comcast guy tells me that the LNB is backfeeding a voltage to the cable modem that is frying the modem. He is going to charge me a $69 service call charge and charge me for replacing the modem.

THe funny thing is that I had my cabel modem installed in September 05 and I had my Dishnetwork installed October 05. It's been working all this time. The comcast guy explained that the back voltage from the Dishnetwork system over time has been slowly frying the modem. You're only seeing the results today.

Does this make sense?

Please explain, that the cable is a pair or single wire, if it is pair, then I believe one cable was used for internet and the other is for Dish system, but what I hear is the diplexer, is thats only a single cable that split in two by the diplexer for both Dish and internet or cable ??

If thats a single cable, then there is the issue, who ever installed later, that need to run another cable, we long knew that internet and satellite in the same cable does creat problem.