Community Forum

signal levels

Xfinity Forum Archive
About the archive project

Xfinity Forum Archive...

This is an archived section of the community.

Content in this area has been identified as outdated or irrelevant.

This change was done in an effort to make the forum easier to use and to keep only the most helpful and recent content active.

Post your questions in the Xfinity Community

Regular Visitor

signal levels

How do I get to a technician service call without going through normal run around "have you tried plugging in your modem? what color are the lights? let me reset it from my end. Do you have a xfinity modem?"  I have had signal problems for a long time they come out replace a splitter once in awhile but that is only a temp fix. I have a SB8200 fresh out of the box today, manual specificaly lists an acceptable range of signal, I am not in that range, so it reboots all the time. I have a 25 yr old house, can we explore the posibility that I am smart enough to plug in my modem and the problem may be outside of the house or degraded cables please?

Screenshot-2018-5-4 Status.png
Regular Visitor

Re: signal levels

forgot event log

Screenshot-2018-5-4 Event Log.png
Frequent Visitor

Re: signal levels


Based on everything you've sent, your signal levels look decent.  Better than maybe 50% of what I often see.


Remember that any SNR over 33dB is effective for QAM256 (DOCSIS 3.0 channels), which you're being offered and a bit higher on the 29th channel in your screenshot, which is your DOCSIS 3.1 OFDM channel.


If your signal is within +/- 7dBmV --and-- your SNR is in the 36dB+ range, you should be looking elsewhere for the issues.


Your upstream signal is running a tad-hot towards the high-end, but definitely not something to worry about.


Based on your logs, more than likely, it looks to me like you have noise on the upstrea (aka reverse/return) side.  You see all the C3 sync issues, then subsequent resets?  That is a glaring indication of trouble handshaking with the headend.


Because your signals are in-line with specs, this indicates that it's related to noise (or similar), not signal level.  Definitely the best route is requesting escalation here on the forum, I think.


Speaking to your original question of how you get the tech to skip the non-sense "did you plug it in", etc --  A couple tips...


1. Always provide a well-thought, sussinct description that is hard to argue down to a simple problem.  I do this by addressing any simple-theories they'll throw out, as part of my question. For example "it cannot be XYZ, because I've tested ABC and that works fine."

2. After they reply with something scripted, like "Okay typony, we'll get this fiured out."  Stop them right there.  Say to them "Thank you, can you repeat your understanding of the problem to be sure there is no miscommunication?"  Once you do this, it forces them to stop and diverge from the script, and realize this is likely something that needs to be escalated (in your case).

3. Immediately explain, politely, why their "troubleshooting" is not relevant while placating them somewhat, then after a bit, explain that you need to be "escalated" to someone that specializes in diagnosing line-noise between you and the CMTS.  When they talk over you, stop them, ask politely if they heard you, then explain that we've established this is not something that can be fixed on this call and you need it escalated.  Then be a bit more forceful in your explanation to escalate, if required.


Overall, I think you'll be in good shape because there isn't too much mystery in the details you provided!  I hope that helps Smiley Happy


Re: signal levels

I've asked an employee to check the CMTS for real-time and historical RF signal reports from your modem. They can also check your local node/plant for any degradation or error reports. You can expect a reply in this thread. 

I am not a Comcast Employee.
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!
Regular Visitor

Re: signal levels

Okay thanks for the help, I will try to reach a tech today.

Regular Visitor

Re: signal levels

Thanks for the advise. You suggested I request escalation here on the forum, I am having trouble finding how to do that on here. Could you piont me in the right direction please?

Official Employee

Re: signal levels

Hi typony, 


No need to look for the escalation process on here, that is something that @nerburg has taken care of for you. I can take a deeper look into the health of the node in your area as well as any other issues that may be causing your problems. In order assist you, please send me a private message verifying your first and last name, and the full account number or phone number associated with your services.


To send a private message click on my name "ComcastChe", then click private message me.

I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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!