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Guest Message by DevFuse

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Spark coming from Coax


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28 replies to this topic

#21 OFFLINE   nmetro

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Posted 02 May 2012 - 05:17 PM

I have DISH for TV, COMCAST for internet. In my set up, Comcast only connected one cable to run to my home office to connect their service. My DISH connection, has two feeds only going to the satellite. Two other feeds are turned off. COMCAST placed a junction box at the point where the cables come from my house to a central point, in back of the garage. In no case, are the two systems are connected to each other. Though, it makes it easy to add more rooms to my satellite service in the future.

So, it sounds like whoever set up the service, described above, decided to merge both systems. Not only is this a bad idea, it could potentially damage the Comcast Internet Modem, equipment connected to the modem (most likely a wireless router) and affect the signal fro DISH, as well. Not to mention, it could damage DISH equipment. Two incompatible system requiring two different electrical requirements.

As others have suggested, either get a eletrician or have both DISH and COMCAST come out, at the same time, if possible, to straighten out this mess. If not, this could prove very expensive for any equipment connected via COAX.

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#22 OFFLINE   harsh

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Posted 04 May 2012 - 08:20 AM

There is technically nothing wrong with diplexing and it does NOT necessarily risk equipment on the either side if done right (and it is pretty hard to mess up). There are two real issues:

1. Insertion loss (the more connections, the weaker the signal)

2. At some point, CATV may decide to run their voice or data services at frequencies >900MHz and that may kill your voice/data service.

Unless you're stupid or lazy enough to plug the CATV cable into the SAT port or only use one diplexer, you're safe from injected voltage on both sides of the diplexer pair.

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#23 OFFLINE   bigglebowski

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Posted 04 May 2012 - 08:54 AM

No crawl space underneath...so it sounds like I need to somehow figure out a way to get a cable from the panel in the laundry room (where each bedroom terminates and comcast comes in) to the outside entry point of comcast's wire on the side of the house.

Not sure how you could do this without tearing open the walls or running a cable out in the open.


At the distribution place is the house phone wiring there? Is it at least cat3 or cat5? Does one of the lines run to the room where you want the modem?

This is what i did, moved my modem to the other side of room (utility shed) from where all coax and phone lines go. Figure out which phone line outside goes to the room where router is and replace rj11 plate with a keystone rj45 jack. From that jack a 25' cat5 jumper ties it into my router.

In my case the phone wiring was cat3 with only 4 wires in it but thats all network wires use.

#24 OFFLINE   Michael P

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Posted 04 May 2012 - 10:19 PM

Everything with the following setup was working flawlessly until about 2 weeks ago. Internet started going up and down all the time and continues. Comcast tech came out and said everything is fine and then he disconnected the Dish coax coming FROM the VIP722, when he disconnected it, and saw it spark against the diplexer while moving around. He said that's "bad" and could be causing the problem.

Setup is as follows:
1) Comcast & Dish outside coax --->
2) Diplexer (Dish on the Power Pass side) at home entry point ---->
3) Coax cabling through the home's walls to a main panel in the laundry room (there is typically a splitter here to distribute coax signal to each room but I have removed it and uses a female-female connector to just have coax in one room) ---->
4) Diplexer at room entry point, again power side to dish, non-power side to Cable Internet modem.

Is this spark bad? I thought the whole point of the diplexer is that it passes DC on only one side so it shouldn't be getting back into the Comcast modem? Does Dish normally pass voltage over their coax?

Any thoughts on how to fix/if this is a problem would be appreciated.
thanks


Question: Was the 722 plugged in when the co-ax cable was pulled? If so that is the voltage that controls the LNB's! The LNB cables should never be pulled when the satellite receiver is plugged in. Having the receiver "off" does not cut the LNB control. The receiver is not truly "off" it's in stand-by mode. The receiver gets periodic EPG updates so that voltage is present 24/7.

What is a cable company installer doing messing with the satellite's cables anyway? They are not qualified to work on DBS.


BTW My internet also acted in a similar way as the problem you had. It turned out to be my router dying. I disconnected the router and directly connected the modem (surf board) to my laptop and it works. I lost my broadband to the 622, but once I replace my router that connection should be back up.

Upon rereading your post, it appears you may be using diplexers to combine the LNB and cable for internet. That is the problem! I have a separate co-ax coming inside for the cable broadband. The only connection between the cable broadband and the 622 is via CAT5. ViP receivers can only use special diplexers made for Dish due to the complex signaling - they are not compatible with cable tv.

Edited by Michael P, 04 May 2012 - 10:28 PM.

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#25 OFFLINE   P Smith

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Posted 04 May 2012 - 10:28 PM

echo: post#6 ... post#11 ....

#26 OFFLINE   Wire Nut

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Posted 05 May 2012 - 12:27 AM

echo: post#6 ... post#11 ....

The spark is normal, the Comcast tech obviously shorted the cable against the receiver port.
Replacing the diplexers should buy you some time blahblah, but it will only ever be a temporary solution and a poor one at that. nmetro said it best, somebody didn't do their job correctly by combining the two systems on one cable. I'm leaning toward it being the Dish installer as Comcast techs do not generally have diplexers on them. This is a tough thing to get fixed, should have been done correctly upon installation but unfortunately it is a zero accountability industry.

#27 OFFLINE   Michael P

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Posted 07 May 2012 - 04:16 PM

The spark is normal, the Comcast tech obviously shorted the cable against the receiver port.
Replacing the diplexers should buy you some time blahblah, but it will only ever be a temporary solution and a poor one at that. nmetro said it best, somebody didn't do their job correctly by combining the two systems on one cable. I'm leaning toward it being the Dish installer as Comcast techs do not generally have diplexers on them. This is a tough thing to get fixed, should have been done correctly upon installation but unfortunately it is a zero accountability industry.


Comcast should never touch the satellite co-ax lines. If the diplexers were from the Dish installer than it's Dish that needs to come out and straighten thing out. If any damage is done to your E* equipment you would be responsible - not the cable guy.
An E* subscriber continuously since February 1997.

#28 OFFLINE   bigglebowski

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Posted 07 May 2012 - 05:47 PM

Not recommending that you should fool with any type of coax with voltage on them for fear of damaging equipment but most receivers either Dish/Directv all have protection circuits for shorts. Even modern wall warts and such all have protection circuits rather than fuses to protect even against sustained shorts that may occur.

Again not saying you shouldnt power down your equipment or that a short will never kill a receiver, just saying. Of course modern receivers do seem like they take an eternity to boot when you are standing there waiting :mad:

#29 OFFLINE   P Smith

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Posted 07 May 2012 - 06:02 PM

Not recommending that you should fool with any type of coax with voltage on them for fear of damaging equipment but most receivers either Dish/Directv all have protection circuits for shorts. Even modern wall warts and such all have protection circuits rather than fuses to protect even against sustained shorts that may occur.

Again not saying you shouldnt power down your equipment or that a short will never kill a receiver, just saying. Of course modern receivers do seem like they take an eternity to boot when you are standing there waiting :mad:


The rule is: if you don't know for sure, for 100%, is a device has overload protection, DON'T ASSUME IT HAS !
100% safe to treat it as UN-PROTECTED !




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