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Internet Connection Lost, Arris T25 Modem frozen

PowerGenSeller
Regular Visitor

Internet Connection Lost, Arris T25 Modem frozen

This happens periodically at night, typically around 1:30AM.  My Arris T25 modem will freeze, even the US/DS light and Online lights are on.  The only way I have found to resolve the problem is to power down and then reboot the modem.  I also have to reboot my VOIP devices, my weather station, and several other devices after the modem reboots.  I know that I am not alone with this problem:

https://forums.xfinity.com/t5/Your-Home-Network/Every-11-days-lost-Internet-connection/m-p/3333854#M...

Since I own the modem, Comcast claims it to be an equipment problem (i.e. my problem, not theirs).  The Arris tech support team can't help because they are not in control of what signals Comcast sends to the modem.  Since this happens periodically in the middle of the night, I have no doubt that Comcast is trying to update the software.  Is Comcast aware of the problem, and are they doing this intentionally so that I will rent their modem?  Does anyone know how to get Comcast's attention on this issue?

 

 

BruceW
Gold Problem Solver

Re: Internet Connection Lost, Arris T25 Modem frozen

Please see Internet Troubleshooting Tips. If you still need help, please post your modem's  signal information, especially downstream power levels and SNR, upstream power levels, and error log.

PowerGenSeller
Regular Visitor

Re: Internet Connection Lost, Arris T25 Modem frozen

Here is a link to my Arris T25 info:

https://www.dropbox.com/s/g9m324qm0zvdmww/Arris%20T25%20Info%202020-07-29.pdf?dl=0

The last event happened on 7/28/2020 @ 140AM.

BruceW
Gold Problem Solver

Re: Internet Connection Lost, Arris T25 Modem frozen


@PowerGenSeller wrote: Here is a link to my Arris T25 info ...

The downstream power levels are borderline/too low. Problems like this are often due to poor coax connections or damaged coax cable, usually in or near your home.

If you can't correct this yourself 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/. 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.

PowerGenSeller
Regular Visitor

Re: Internet Connection Lost, Arris T25 Modem frozen

It happened again this morning, 8/11/2020 @ 1:43AM.  That is EXACTLY 14 days since the last time.  

JasonLFarmer
New Poster

Re: Internet Connection Lost, Arris T25 Modem frozen

You are definitely not alone in this issue. I have the exact same issue happening every three days or so, typically around or between between midnight and 1am. My internal network connectivity is solid, yet I cannot get out on the internet. It just happened to me again just now, and a quick google search brought me to your post on this forum. I have Gigabit Internet from Comcast and an Arris T25 cable modem that I purchased myself. Spoke to Arris on multiple occasions, and they blame the signal levels Comcast is sending to me. I spoke to Comcast on several occasions, and all they know how to do is try to reset the modem from their end, only to tell me that they cannot communicate with the modem, and I end up having to pull the plug on it myself. Comcast has come out to test my very basic coax cabling (Their single splitter on the house - one side to X1  cable box, and the other going to cable modem). The say that power levels are within acceptable levels for Comcast service, yet my modem still needs to be manually restarted every few nights.

JasonLFarmer
New Poster

Re: Internet Connection Lost, Arris T25 Modem frozen

I have taken screenshots of the RF Parameters on my modem after the restart. I will grab a new screenshot in a few days just before I restart the modem. I can tell you that just before I restart the modem, there are a high number of Uncorrectables in the Downstream QAM. Just something I've noticed.

 

https://www.icloud.com/iclouddrive/05CoEWrI1sBdNmyVho5RYYIBA#Arris_T25_RF_Parameters_1_of_2_After_Re...

 

https://www.icloud.com/iclouddrive/0XagGQueqDIWMM7cmC36upjPw#Arris_T25_RF_Parameters_2_of_2_After_Re...

 

On one of my calls to Arris about this issue, they told me that the upstream power levels needed to be between 45 and 51 decibels, and the downstream power levels needed to be between -5 and 5 decibels. The comcast tech that came out to my house said that this did not match Comcast standards.

 

Arris also asked me to restart the modem and check the power levels after the restart. On my end, there was no difference in the power levels I receive. My upstream levels are always between 39 and 45 decibels, and my downstream levels are always between 7 and 11 decibels.

GeorgeX1
Contributor

Re: Internet Connection Lost, Arris T25 Modem frozen

This is the EXACT problem I'm having with the T25.  Mine goes out every night at 12:30am Eastern (https://forums.xfinity.com/t5/Your-Home-Network/Internet-outage-at-the-same-time/m-p/3368847)

 

Trying to talk to someone from Customer Service who can speak knowledgably about modem signal strength is impossible.  Arris told me the same things about signal strength.

Per Arris support (https://arris.secure.force.com/consumers/articles/General_FAQs/T25-Troubleshooting-Internet-Connecti...

In the Downstream QAM section, identify the Modulation and Power to verify SNR levels are within the acceptable range for each downstream channel. 
 

Downstream Signal To Noise Ratio (SNR)
ModulationDS Power Level (dBmV)Acceptable DS SNR (dB)
64QAM-15 to 15+23.5 or greater
256QAM-6 to 15+30 or greater
-15 to -6 

 

 

 

For upstream:

n the Upstream QAM section, identify the number of Upstream channels and Symbol Rate to verify the Power levels are within the acceptable range for each upstream channel. 
 

Upstream Transmit Power Level
 Symbol Rate (kSym/s)Acceptable US Power Level (dBmV)
Single
 
 
1280 +45 to +61
2560+45 to +58 
5120 +45 to +57 
Two1280 +45 to +58 
2560 +45 to +55 
5120 +45 to +54
Three or more1280 +45 to +55
2560 +45 to +52
5120 +45 to +51 

 

mercurydonnao
Frequent Visitor

Re: Internet Connection Lost, Arris T25 Modem frozen

Arris T25 has Intel chips which are defective, and no longer recommended by Xfinity.

we are having the same problem with ours, and will be calling Arris tomorrow to try and get a replacement modem, or our money back. This is not looking good though as there is a Class Action law suit in CA right now against Arris and the Intel Puma chip sets.
We can't live with multiple shutdowns every day, and may just buy a different approved modem from Amazon and return it if Arris replaces ours. Have a feeling Arris doesn't want to own this problem though and will give us the run around.
Link to the law suit.

https://topclassactions.com/lawsuit-settlements/pending-settlements/885390-arris-surfboard-cable-mod...

curtis_r
New Poster

Re: Internet Connection Lost, Arris T25 Modem frozen

This sounds all too familiar.  Found our internet down many mornings.  Arris said we had weak Comcast signal.  Comcast came out & changed the coax terminals (which I tend to find insignificant).  A few weeks later, we now lost internet 3 mornings in the past week (but not overnight).  Arris said we now have weak upload signal.

 

Rebooting the Arris doesn't seem to fix it, at least not right away - but I'm of course never home when this happens, and the rest of the family needs to troubleshoot.