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8 Messages

Sunday, August 18th, 2024 4:12 PM

MB8611 rebooting regularly

I have a Motorola MB8611 modem which is on the Xfinity Approved 3rd party list.

3 or 4 times per day, the modem disconnects from the Internet. This usually happens on the quarter past the hour or half past the hour. (+- approx one minute)

I have a script running to monitor

CONNECTION ACQUIRED
connection acquired at: 2024-08-16 21:18:12
monitoring started at: 2024-08-16 21:18:12
disconnected at: 2024-08-17 09:14:35
connected again: 2024-08-17 09:16:34
connection was unavailable for: 0:01:59
disconnected at: 2024-08-17 12:29:26
connected again: 2024-08-17 12:31:09
connection was unavailable for: 0:01:43
disconnected at: 2024-08-18 08:29:23
connected again: 2024-08-18 08:31:27
connection was unavailable for: 0:02:04

Event Log (one hour off from my script)

Attached is what I see on the Modem Connection page a few minutes after the modem comes back online.

Is there anything unusual here?

I do have a good quality splitter going for the TV signal and the internet signal. I replaced it based on other conversations I saw on this support forum but that did not help.

Has anyone else been able to solve this problem?

Thanks in advance for your help.

Official Employee

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1.7K Messages

3 months ago

@user_52qoiy Thank you for reaching out so we can help with your internet stability. I rely on my internet every day for school and work so I know it's important to have a a strong connection. Have you checked the coax cable at the back of the modem and the coax wall plate? Are both ends securely tightened? Are you using a router alongside your modem? 

8 Messages

Thank you Emily. All coax connections appear to be tight.

I am using a router - Google Nest Wifi router.

Official Employee

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1.3K Messages

We greatly appreciate you checking the coax connections @user_52qoiy. Would you happen to ensure the coax cable is in good shape as well such as no hard bends, kinks, bite marks, or cuts? These things could interfere with the signal quality levels to and from the modem. Have you also attempted to bypass the cable splitter to see if that helps the signal levels reach your modem to provide a smoother and more reliable service?

Do you also have the Xfinity App on your mobile device? The Xfinity App is the go-to app for anything related to the Xfinity account, billing, and services. Within the Xfinity App, you should be able to select Internet and have our Xfinity Assistant perform a quick Whole Home Network test to see if the test provides any results? 

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8 Messages

Thank you - I ran through the app assistant but nothing was found.

My cable does route through a splitter but I have tested with no splitter in the past.

It is possible that there is another splitter that I am not aware of (under the house for example).

Gold Problem Solver

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26K Messages

3 months ago

... 3 or 4 times per day, the modem disconnects from the Internet ...

The downstream power levels and SNR values are borderline to out of spec (too low), and the upstream power levels are also out of spec (too high). Network connection problems like this are often due to poor coax connections or damaged coax cable, usually in or near your home. Running the cable through a surge protector, a defective splitter, or too many splitters can cause signal problems as well. If there is an amplifier in the line make sure it's getting power. 

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, respond to the employee's message above, or 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/. It's not likely they can fix the problem remotely. If not, 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 (approx $100) 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.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

8 Messages

3 months ago

Thanks BruceW. That is useful information.

8 Messages

2 months ago

Quick update - I found two separate 3 way splitters under the house. I have isolated the cables that feed the cable modem and disconnected the rest. The cables still go through one 3-way splitter (with nothing else connected) as I currently do not have a way to join them.

There is not much difference in power or SNR however.

I plan to find a cable joiner to see if that makes a difference.

8 Messages

2 months ago

After removing the extra 3-way splitter and using a coax joiner instead, I think these numbers look better.

Upstream power level is a little over on 2 channels but not as bad as before.

Official Employee

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2.2K Messages

Thank you for all the steps you have taken to try and get the internet service working as it should be, user_52qoiy! I am glad that removing the extra splitters helped. I have 1 splitter left in my home and bought caps for the ends that are not in use. How is your service working now? 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

8 Messages

The modem has not disconnected in over 3 days now which is a record.

Official Employee

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2.2K Messages

That's great that there have been no disconnects in 3 days, @user_52qoiy! We are still going to monitor this to ensure there are no further problems. I will reach back out in a week. If you notice any problems before then, please let us know here. 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Official Employee

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1.8K Messages

Hello, @user_52qoiy! I hope you're doing well. I wanted to check in on the connection. Is it still working properly? 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick
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