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Comcast tech says SB8200 modem bad; Arris says Comcast signal is bad - UGH!

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Comcast tech says SB8200 modem bad; Arris says Comcast signal is bad - UGH!

Model: SB8200 (8 months old)

 

Symptom: Intermittant performance issues. Initial problem was my speeds weren't going over 1mbs (on 250 mbit service). 

 

Solution: Level 1 support had me to several reboots but no change in speed. A technician was scheduled but in the meantime I did a factory reset of the modem and the speeds returned; I didn't cancel the tech. His tests failed for values on 4-5 channels (he had little understanding to what that meant). He replaced every cable and fitting he could get his hands on and he moved to several different ports on the pole. The signal values didn't budge. Finally, his supervisor concluded it must be a bad modem. 

 

I immediately called Arris support and they asked me for the range of values in the log and told me they should all be: 

-15  to 15 Power

-6 to 15 SNR 

 

They said Comcast needs to adjust those values on their end and the tech (who had already bolted) could not have done anything. Things are ok right now, but the modem eventually reaches a point where it either slows down or stops responding completely and needs a power cycle. If the range given by Arris is correct, then some of these numbers don't look good to me. Any advice?

Screen Shot 2019-07-10 at 8.40.53 AM.png

Screen Shot 2019-07-10 at 8.41.10 AM.png

 

My images aren't working for some reason so here's the link: Page 1 and Page 2

 

The last messages logged are:

 

07/09/2019 19:08 74010100 6 "CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=f8:f5:32:f1:35:b1;CMTS-MAC=94:d4:69:54:f7:1e;CM-QOS=1.1;CM-VER=3.1;"
07/09/2019 19:08 74010100 6 "CM-STATUS message sent. Event Type Code: 4; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=f8:f5:32:f1:35:b1;CMTS-MAC=94:d4:69:54:f7:1e;CM-QOS=1.1;CM-VER=3.1;"
07/09/2019 19:08 74010100 6 "CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0.;CM-MAC=f8:f5:32:f1:35:b1;CMTS-MAC=94:d4:69:54:f7:1e;CM-QOS=1.1;CM-VER=3.1;"
07/09/2019 19:08 74010100 6 "CM-STATUS message sent. Event Type Code: 1; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=f8:f5:32:f1:35:b1;CMTS-MAC=94:d4:69:54:f7:1e;CM-QOS=1.1;CM-VER=3.1;"
07/09/2019 19:08 84020300 5 "MDD message timeout;CM-MAC=f8:f5:32:f1:35:b1;CMTS-MAC=94:d4:69:54:f7:1e;CM-QOS=1.1;CM-VER=3.1;"
07/09/2019 19:03 74010100 6 "CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0.;CM-MAC=f8:f5:32:f1:35:b1;CMTS-MAC=94:d4:69:54:f7:1e;CM-QOS=1.1;CM-VER=3.1;"
07/09/2019 18:13 74010100 6 "CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0.;CM-MAC=f8:f5:32:f1:35:b1;CMTS-MAC=94:d4:69:54:f7:1e;CM-QOS=1.1;CM-VER=3.1;"
Expert

Re: Comcast tech says SB8200 modem bad; Arris says Comcast signal is bad - UGH!

Can't see your pics. Since you are a new poster, they likely need to be approved by a Forum Admin. Or you may need to make a minimum number of posts.

You could try hosting them at one of those free third-party pic hosting sites like Imgur or Photobucket and post the link to them here.



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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New Poster

Re: Comcast tech says SB8200 modem bad; Arris says Comcast signal is bad - UGH!

 


@EG wrote:

Can't see your pics. Since you are a new poster, they likely need to be approved by a Forum Admin. Or you may need to make a minimum number of posts.

You could try hosting them at one of those free third-party pic hosting sites like Imgur or Photobucket and post the link to them here.


Thanks for letting me know! I posted imgur links.

Expert

Re: Comcast tech says SB8200 modem bad; Arris says Comcast signal is bad - UGH!

The downstream power is weak on the lower channels/ out of spec on the higher frequency channels. Looks like a "cable tilt" problem. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

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 get the techs involved again to investigate and correct if nothing above applies.



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New Poster

Re: Comcast tech says SB8200 modem bad; Arris says Comcast signal is bad - UGH!


@EG wrote:

The downstream power is weak on the lower channels/ out of spec on the higher frequency channels. Looks like a "cable tilt" problem. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

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 get the techs involved again to investigate and correct if nothing above applies.


Thanks for the reply. Given that there's only one splitter (3-way) that was supplied by the tech to replace the existing one (which was also comcast-tech supplied) and they replaced all the fittings, the drop to the pole, and even bypassed all the connections with a direct link, what's left??? They were hesitant to put in a ticket to replace the drop on the pole (whatever that box with all the drops is called). 

Expert

Re: Comcast tech says SB8200 modem bad; Arris says Comcast signal is bad - UGH!

It may very well be the drop line from the pole or the "tap" itself. Bear in mind that if the premises facing techs cannot find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. Good luck with it !



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Official Employee

Re: Comcast tech says SB8200 modem bad; Arris says Comcast signal is bad - UGH!

Hello, pdanna! Thank you so much for reaching out to us. I can check if there are any issues in your area and see if I can access a ticket you have mentioned. Could you please private message me your first and last name? Click on my name ComcastElla, then click Send a message.


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