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Arris SB6183 and high upstream power signal - internet goes down

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Regular Visitor

Arris SB6183 and high upstream power signal - internet goes down

Hello everyone,

 

Starting this week I am having constant issues around 10AM-12PM CST on my modem. Xfinity website says it can't connect to my modem because signal is getting lost. When i go to check the stats this is what I am getting

 

https://imgur.com/a/vfOfYK7

 

According to Arris website my powers signals should be within 45 dBmV and 51dBmV, as you can see 3 out of 4 are over 51.

 

https://arris.secure.force.com/consumers/articles/General_FAQs/SB6183-Troubleshoot-Internet-Connecti...

 

Sometimes one restart of them modem is enough but today I did it 5 or 6 times and issue is still persisting.

 

Can anyone can assist with this please?

 

Sincerely,

papski

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Gold Problem Solver

Re: Arris SB6183 and high upstream power signal - internet goes down


@papski2 wrote: ... According to Arris website my powers signals should be within 45 dBmV and 51dBmV ...

Comcast specs for upstream power are +35 dBmV to +50 dBmV, so all 4 channels are out of spec. Network connection problems are often due to poor coax connections or damaged coax cable, usually in or near your home.

If you want to troubleshoot this yourself, please see Internet 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 a faulty Comcast rental device, or anything outside your home, you shouldn't be charged.

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Expert

Re: Arris SB6183 and high upstream power signal - internet goes down

The upstream power is too high and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.



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Expert

Re: Arris SB6183 and high upstream power signal - internet goes down

.@BruceW. Ya' beat me by a split second 😋   😆



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
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Gold Problem Solver

Re: Arris SB6183 and high upstream power signal - internet goes down


@EG wrote: @BruceW. Ya' beat me by a split second 😋   😆

Gotcha!   😁

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Expert

Re: Arris SB6183 and high upstream power signal - internet goes down

😜



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
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Regular Visitor

Re: Arris SB6183 and high upstream power signal - internet goes down

@EG @BruceW ;
thank you for your replies, this is how it is setup for over a year https://imgur.com/a/S8ulOtu From what I know this cable goes directly outside and from there it goes stright to the pole. There are no other equipment or services in the house provided by Comcast except this internet line. I am unaware of any splitters or amplifiers unless they are outside the house (which would be on Comcast to replace free of charge, correct?). Where can I buy good quality coax to replace mine? Bestbuy?

EDIT: this is how it looks outside https://imgur.com/a/LHkidWe

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Gold Problem Solver

Re: Arris SB6183 and high upstream power signal - internet goes down


@papski2 wrote: ... Where can I buy good quality coax to replace mine? ...

If coax looks damaged, it needs to be repaired or replaced. But if it looks OK, you need specialized test equipment to determine if it actually IS OK. Worse, it may be OK one minute, and not OK the next. Impossible to determine those things just by looking at the cable.

 

Do you have reason to believe you need to replace the coax? Note that failures at connection points are probably more common than failures in the cable itself. If you do need to replace cable or connectors, RG-6 quad shield from most any reputable supplier with compression (not crimp) connectors and the tooling to apply them should be fine.

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Regular Visitor

Re: Arris SB6183 and high upstream power signal - internet goes down

@BruceW 

 

I was just wondering if it is worth a shot to check COAX before calling in Comcast. I've already ordered a new one but it might come later next week. If after replacing it issues are still there I will give comcast a call and mention to come between 10AM and 12PM when issue is  happening every day. It is 10AM and my upstreams are over 51, at 6AM all of them were around 49 (which I assume is still very high)

 

EDIT: Forgot to mention, I see bunch of T3 and T4 errors on modem, which is expected with that signal