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Modem Denied Access

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New Poster

Modem Denied Access

Modem error log and current up/downstream issues. 
SB1683 modem.

 

https://imgur.com/a/9xbkZC9

 

Issue started about 4:00 PM MT. Cable modem reset and now am unable to get a signal. 

 

Troubleshoot steps I have tried: 
1) Removed splitter from main cable line.

2) Reset modem (multiple times)

3) Tried the cable line going into my house same issue. 

 

At this point, I have to imagine this is on Comcast's side. Who can I talk to in order to get this issue resolved?

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Gold Problem Solver

Re: Modem Denied Access

Your modem has lost its connection to Comcast's network. Network connection problems  are often due to poor coax connections, usually in or near your home.

If you want to troubleshoot this yourself, please see Connection Troubleshooting Tips. If you can't find the problem or you'd rather have Comcast take care of it, call them at the phone number on your bill or 1-800-Comcast, or use one of the options on https://www.xfinity.com/support/contact-us/. If they can't fix the problem remotely (unlikely), insist they send a tech out to identify the cause and correct it.

If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit unless you have their Service Protection Plan (https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to anything outside your home, you shouldn't be charged.

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New Poster

Re: Modem Denied Access

Bruce - Thank you for the reply however your canned response does not help in this situation.

I checked my modem from the junction box on the side of my house and did not receive internet. After about an hour and a half, my internet came back. 

At this time, my internet issue is due to out of spec power levels provided by comcast. As you can see if my original images the power supplied to my upstream channels is not within manufacturer settings. For the SB6138 modem, upstream power leverls need to be between 45 and 51 dBmV and I am well below at at 26. 

Comcast will need to increase my power level so I am receiving the correct service. A call will be placed to Xfinity.

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Gold Problem Solver

Re: Modem Denied Access

Sorry to disappoint. You stated:

  •  ... upstream power leverls need to be between 45 and 51 dBmV ...

Two things about that:

  1. Arris began saying this more than a year ago. I don't know why, because it's nonsense. Comcast's signal specs are the ones posted in the Connection Troubleshooting Tips Forum article, which says the Upstream Power Level at the modem should be between +35 dBmV and +50 dBmV. The level is controlled by Comcast's equipment and does not need to be above 45 dBmV. In fact, many customers have service that works perfectly fine with upstream power levels below 45 dBmV. Some even operate with the upstream below 35 dBmV.
  2. Your modem was not fully synced up with Comcast's head end at the time you took the readings you posted. As such, the accuracy of the readings are questionable. Also their equipment was probably not communicating with the modem well enough to establish normal upstream power control. The out-of-spec value you posted doesn't really tell us much.
  • ... A call will be placed to Xfinity.

As it should be whenever your are having problems that you are able to correct yourself.