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user_c6d28a
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Tuesday, September 20th, 2022 4:03 AM

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Motorola MB8611 modem frequently loses connection to Xfinity/reboots

I have a Motorola MB8611 cable modem that I purchased from Best Buy in June 2022 to use with Xfinity's gigabit cable internet service. I've been encountering a problem where the modem seems to drop its connection to the WAN/Xfinity and reboots, causing my home network to lose Internet connectivity for 5-10 minutes. This problem occurs multiple times a day, sometimes as often as three or four times an hour.

I factory reset my modem in case it was an issue with buggy firmware or something, but that didn't seem to work.

I've looked around the forums and have seen that multiple other users have had similar issues with this model of modem, but I'm not sure if it's a problem on my end, with Xfinity's config for the modem, or with the network infrastructure in my house or neighborhood.

If anyone has any troubleshooting ideas or can escalate this to Xfinity's technical support staff, I'd really appreciate it - this issue has been driving my family nuts.

I was able to collect the following info from my modem:

Device Information:

 Cable Specification Version DOCSIS 3.1
   Hardware Version V1.0
   Software Version 8611-19.2.18
   Cable Modem MAC Address [redacted]
   Cable Modem Serial Number 2621-MB8611-30-3113
   CM Certificate Installed
    Prod_19.2_d31

Connection information:

Event Log:

Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted]0;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
22:49:52
Mon Sep 19 2022		 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
22:50:08
Mon Sep 19 2022		 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0.;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;

Question

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Updated 

2 years ago

 • Edited

5.3K

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user_c6d28a

Visitor

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5 Messages

2 years ago

This issue is continuing to occur very frequently (twice in the last fifteen minutes alone). Any help would be appreciated, as this is rendering our home internet basically unusable for large periods of time.

I was able to capture more event logs:

Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
02:13:15
Tue Sep 20 2022		 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
02:13:49
Tue Sep 20 2022		 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
02:33:49
Tue Sep 20 2022		 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
02:34:19
Tue Sep 20 2022		 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:82:e3:2a;CMTS-MAC=00:01:5c:7e:02:66;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
09:08:23
Tue Sep 20 2022		 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;

(edited)

3

0

XfinityAmira

Official Employee

 • 

3.8K Messages

Hello @user_c6d28a, thanks for taking the time to reach out to us on our Forums page. We can't thank you enough for being a customer with us, and I am sorry to hear about the connection issues you have been experiencing. I certainly know the importance of having a solid and steady connection, and my team would love to further look into / troubleshoot this on our end. To best assist you, please send us a Private Direct Message. 

Here are the detailed steps to direct message us: 
 • Click "Sign In" if necessary
 • Click the "Direct Message icon” (upper right corner of this page)
 • Click the "New message" (pencil and paper) icon
 • Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
 • Type your message in the text area near the bottom of the window
 • Press Enter to send your message

 

 

Thank you @EG for your help and getting this escalated, very much appreciated! 

 

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

2 years ago

user_c6d28a

Visitor

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5 Messages

Thanks, I've DM'd the support team. I'll update this forums post when I hear back.

2 years ago

0

hillvolfan

Visitor

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1 Message

I had to contact Motorola support -

[Edited: "Personal Information"]
M-F 8:30 AM - 10:00 PM ET

They told me that there were MANY of the same issues (I had the same issue - VERY frustrating).  In my opinion it maybe QA with Xfinity but just my opinion.

Anyways, they had me fill out some information and they sent me a replacement that they "said" should work.  Same version of the modem we all have.  It took a week to get to my house.  I have to send the original one back to them within 30 days.  It has been up a day so far with no issues (have only had it a day so far).

I had Xfinity come to my house 6 times checking everything.  They changed up a lot of things but alas I hope this finally resolves my problems.

Give that number a call and hopefully it will help your issues too.  I did have to leave my number b/c I didn't want to wait in line AND my cell phone relies on WiFi for coverage and the modem was losing connection every 5 mins.

(edited)

2 years ago

0

EG

Expert

 • 

106.6K Messages

2 years ago

The signal status values at that snapshot in time were good but the error log entries indicate that something is going on. Perhaps there is noise ingress into the line(s) /  an upstream channel / return path impairment somewhere.

There are other signal stat values that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.


I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They will be able to poll the CMTS (Cable Modem Termination System) to check for any real-time degradation and / or error reports, see your node / cable plant, and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.


You should get a reply here in your topic. Good luck !

1

user_c6d28a

Visitor

 • 

5 Messages

@EG​ Thanks, I've DM'd Xfinity support. I'll update this post if I hear back with any useful info.

2 years ago

0

EG

Expert

 • 

106.6K Messages

2 years ago

@user_c6d28a 

You're quite welcome ! And please do.

0

0

user_10b3c9

Visitor

 • 

1 Message

2 years ago

I am having the exact same issue, xfinity has sent a tech out to my residence twice and improved everything that they can on their end.  The only reason i bought this modem model was because it was on xfinity's list of approved modems and had good reviews.  

0

EG

Expert

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106.6K Messages

2 years ago

@user_10b3c9 

Please create a new topic of your own here on this board detailing your issue. Thanks.

0

0

user_c6d28a

Visitor

 • 

5 Messages

2 years ago

Update:

After reaching out to Xfinity Support, they set up an appointment for a tech to come out to our house and take a look at the issue. However, a day or two before the appointment, Xfinity called to say that a tech had made a change to equipment outside the house (though they didn't elaborate on what they specific change actually was), and that the issue should be resolved. At first, things did indeed seem better - our modem had over a day of uptime without any interruptions - so we cancelled the in-house tech appointment, since it seemed like the issue was resolved.

However, over the past day or two, the issue seems to have returned - more T3 timeouts and modem reboots, although our modem doesn't seem to be rebooting *quite* as often. I've attached more logs below:

Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:82:e3:2a;CMTS-MAC=00:01:5c:7e:02:66;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
11:41:13
Sun Sep 25 2022		 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[redacted];CMTS-MAC=[redacted];CM-QOS=1.1;CM-VER=3.1;



I'm assuming we need to make a new tech appointment and have them out to take a look?

(edited)

2

CCJess

Problem Solver

 • 

323 Messages

Hello @user_c6d28a I am sorry to hear that the service issue came back after a few days, this isn't the experience we want for you as a valued member of the Xfinity family. Can you please send us another message using the live chat to continue with this? 

I no longer work for Comcast.

2 years ago

0

user_Es0824

Contributor

 • 

70 Messages

@user_c6d28a​ Are you still having this issue?

2 years ago

0

user_e3c446

Visitor

 • 

3 Messages

2 years ago

were you able to resolve this?  I just got an MB8611 and am having the same issues.  it's driving me crazy.  It sounds like I should just swap out the modem for a fresh unit

0

JerryEF

Visitor

 • 

1 Message

2 years ago

Having the same problems for a few months.  I am now in a position where I cannot connect to the internet. After spending hours on phone with Xfinity support and swapping out the MB8611 for a spare MB8600 I had available, I still have no service. I am told every thing looks good from their end, yet I have no connectivity. Their final recommendation is to call Motorola. Of course, today is Saturday and Motorola service says to call back on Monday.

Lack of Xfinity support is very frustrating. I may be ready to call Verizon to see about a FIOS line.

(edited)

1

CCJamie

Problem Solver

 • 

322 Messages

@JerryEF Sorry to hear that you are having trouble with your internet connection. I can definitely look into this with you and help find a resolution. Would you please send a direct message with your name and complete service address? 

To send a "Direct Message" to Xfinity Support:

Click "Sign In" if necessary

Click the "Direct Messaging" icon or https://comca.st/3EqVMu7

Click the "New message" (pencil and paper) icon

The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there

 - As you are typing a drop-down list appears. Select "Xfinity Support" from that list

 - An "Xfinity Support" graphic replaces the "To:" line

Type your message in the text area near the bottom of the window

Press Enter to send it

I no longer work for Comcast.

2 years ago

0

user_fd33c8

Contributor

 • 

45 Messages

2 years ago

Have you figured out the issue? Exactly the same problem here with Motorola 8611   losing connection and reboot 2-3 times a day. Very frustrating.

2

user_e3c446

Visitor

 • 

3 Messages

@user_fd33c8​ Its the modem! After two weeks and an in person xfinity appt I swapped the bad mb8611 for an arris surfboard and have had no problems! I also recommend getting a well reviewed cat 6 cable (i got the one from best buy) as it increases the speed to the router compared to the cable the modem comes with it

2 years ago

XfinityVianney

Official Employee

 • 

1.7K Messages

Hi, @user_fd33c8. I see you are having a similar issue with your Motorola equipment as well. I know everything situation is different, and we will be glad to help. Have you reviewed your event logs as well? If so, are you seeing any timeouts or red flags there? 

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

2 years ago

0

user_be3ca5

Contributor

 • 

11 Messages

2 years ago

I am having the same issue, disconnects hourly with T3 timeouts and diplexer warnings/issues. This has been happening for the past week. Tech visited yesterday but issue remains. This is not a Motorola cable modem issue, Comcast is attempting to push a firmware update or update of some kind and is causing issues with the MB8611, which is an approved Comcast cable modem. Check out how many posts are related to MB8611, does anyone really think that these many Motorola cable modems are "faulty" and need to be replaced? That is nonsense, it is a comcast issue and comcast should be working to resolve it. 

0

macster1

Regular Visitor

 • 

3 Messages

2 years ago

Unfortunately, I have the same problem with my MB8611.  With so many of us having the same issue, it points to Comcast to figure it out for all of us.  So many people so frustrated for the lack of a timely resolution.  Hope it happens sooner that later.  Has anyone sent their data dump to Motorola to get their input if their the MB8611 doesn't work with Comcast?

4

user_Es0824

Contributor

 • 

70 Messages

@macster1 This is what Motorola has sent me after reaching out to them​

2 years ago

macster1

Regular Visitor

 • 

3 Messages

Pls advise if Comcast changes your cable and the issue goes away.  Odd that other modems seem to be working ok!

2 years ago

user_Es0824

Contributor

 • 

70 Messages

@macster1​ I have a tech coming out tomorrow. However, I have attached an attenuator to my modem and I have been online for over 21 hours straight so I am crossing my fingers that it stays that way. I've also seen people with netgear and Arris modems having issues as well. 

2 years ago

0

user_Es0824

Contributor

 • 

70 Messages

@macster1​ no luck. I have a test xfinity gateway currently and its working perfectly. 

2 years ago

0

user_mf3213

Visitor

 • 

3 Messages

2 years ago

Has anyone found a root cause/fix for this yet?  I just recently purchased the MB8611 after my internet speed was increased and the modem was on the approved list.  I experience connection drops multiple times per day for a few minutes.  This is beginning to impact work and is incredibly frustrating.  I've tried all of the normal troubleshooting, and nothing is improving my situation.  Should we be expecting Xfinity to fix something here or do I need to figure out another modem to use?  Very frustrated...

5

user_Es0824

Contributor

 • 

70 Messages

@mferry32​ What are your logs and connection stats? An attenuator so far has worked for me (26 hours without crash rn, granted I once got to 39 hours and then it started shutting down again). Has kept my levels in check. Cause is bad firmware from xfinity. They haven't come out and said anything about it but that is the working theory for at least myself and some others who I've seen posting on here and on reddit. You should expect Xfinity to fix this. How long it will take, idk because they aren't even acknowledging the issue. 

2 years ago

user_mf3213

Visitor

 • 

3 Messages

[Image Removed: "Personal Information"] Here is the latest log updates.

(edited)

2 years ago

0

XfinityChristina

Official Employee

 • 

923 Messages

Hi, @user_mf3213. We don't have a known solution just yet. When you purchased the new modem, did you have us add it to the account and activate it? I ask because we have to add it on our end to make sure it's activated properly. Did these issues start before or after you got the new modem? 

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

2 years ago

0

user_mf3213

Visitor

 • 

3 Messages

I used the mobile app to add/activate the modem.  This issue started after activating this modem.  My previous modem did not have any issues, but it wasn't compatible for the speed upgrade I received.  When I contacted Xfinity support, they notified me that they made some changes to my settings on their end.  If the problem persists, I will need a local tech to come on site and investigate further.  I don't want to waste anyone's time if this issue is more widespread and not specific to me given how many people are experiencing the same exact issue with this modem and Xfinity service.  

2 years ago

XfinityDilary

Official Employee

 • 

1.8K Messages

Thanks for clarifying, @user_mf3213. I am not aware of any widespread issues with this specific device. I know you mentioned already taking some basic troubleshooting steps. I appreciate you taking those steps in advance. It's always a good start. The next step would be to check the signal on our end. Could you please send our team a private message with your full name and full address? Our team can most definitely take a further look at this issue.

 

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2 years ago

0

user_fd33c8

Contributor

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45 Messages

2 years ago

Update: I replaced 100 ft of coaxial cable myself and inspected/tightened connections in the demarc box between RG11 and RG6 cables. My modem has been up for 2 days 16 hours now without a reboot (fingers crossed). Software version is still 8611-21.3.7. In my event logs I only see now "RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW" warnings, which indicate that my upstream power fluctuates a couple of times per day (from 38dB to 47dB, but at least connection is stable and no drop-offs/reboots). That fluctuation corresponds to new event log warning. According to the author of this article https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html this may indicate a lose connector somewhere on the line. The only place is left for me to inspect is the cable box on the sidewalk near my house from where RG11 originates. Hope this helps.

(edited)

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user_b3faf8

Visitor

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14 Messages

2 years ago

Having a similar problem with constant reboots - brand new MB8611 - any help on this issue?

11

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user_fd33c8

Contributor

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45 Messages

@user_b3faf8​ Read this article https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html and inspect all your cables and connections to begin with

2 years ago

0

user_b3faf8

Visitor

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14 Messages

Interesting.  I went to home depot and bought a cable, and am going direct from the modem into the box.  I guess we will see what happens.  My power numbers went up slightly, but the new cable is a lot shorter than the original run.  25 minutes and counting. 

(edited)

2 years ago

user_b3faf8

Visitor

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14 Messages

It died again.  Got about an hour and 20 minutes from it.

2 years ago

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user_b3faf8

Visitor

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14 Messages

Screen 1 - Power levels on new cable

2 years ago

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user_b3faf8

Visitor

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14 Messages

Screen 2 - Power levels page 2

2 years ago

0

EG

Expert

 • 

106.6K Messages

2 years ago

@XfinityErika 

Hi Erika. I think that you got the wrong thread here.

(edited)

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