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Trying to determine if the refurbished modem I just bought from Amazon is the problem for extremely slow speeds or if the modem is bad. Following steps I found in FAQs, I got the attached results but I’m too confused to make sense of it.

 

Has your ISP actually “provisioned” the modem on your account?

On the upstream side, I’m surprised to only see 3 channels.

On the downstream side, you have generally good signal levels and signal to noise levels, though a bit more variation than is ideal. Something is clearly wrong with channel 13. 

I’d reboot, check your Status Startup screen and confirm everything completed correctly (see image below). If everything completes, check your signal again. If you see issues, reach out to your ISP first.

 


I worked with Xfinity to setup the modem and have rebooted numerous times. My download speeds have ranged from low 20’s to 50 with this modem. With Xfinty’s Gateway, the range was 120’s to 200. Does what you see explain this? Do you think that a new Arris would perform better? This one is refurbished. I understand very little about this technology so appreciate your help.


From what I see, I think there is a signal issue, but it is certainly possible there is an issue with the modem. Did you return the gateway? It would help if you had before and after signal levels. 

 


 

Yes, doggone it, I returned the Gateway. I think I will return this refurbished modem and buy a new one that I can trust. If that doesn’t work, then I’ll know the problem is Comcast. Thanks again.


Good luck! The new ones were on sale at Best Buy for about $120 but it looks like the price has gone back up. I bought one, and kept it, just to ensure some issues I was seeing were not modem specific. I still have a perfectly good MB8600 now as a backup.


Lucky you! I thought that since I was able to buy an Asurion extended warranty with this product that it must be in good condition. Maybe it is but I cannot tell.


This is from the event log. Does mismatch .indicate a problem with the modem or Comcast?

 
10/02/2023 20:06 73050400 5 "REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;"
10/02/2023 20:06 67061600 6 "DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;"

Event logs are monitored only by your internet service provider.

Since you are experiencing with slow speed internet, also you shared the cable signal levels.

As I checked the cable signal levels, Upstream power levels are not in range. It should be greater than 45dbmv and currently it is 38dbmv.

I suggest you to contact your internet service provider and ask them to adjust the cable signals to fix this issue.


Thank you! I have no idea what any of this means or how to identify what is a result of the cable speed as opposed to the modem. I’ll call Xfinity before I give up and return the modem.