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SB6141 Keeps disconnecting

New Poster

SB6141 Keeps disconnecting

Unfortunately for the last week I have gotten the dreaded 'modem disconnect' bug.. I've read others on this topic and here's my info..


Signal to Noise ratio:

37 dB  37 dB  38 dB  37 dB  38 dB  38 dB  38 dB  38 dB 


Power Level
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading
6 dBmV   7 dBmV   7 dBmV   6 dBmV   6 dBmV   6 dBmV   6 dBmV  

6 dBmV 


Upstream Bonding Channel Value
Channel ID 63  61  62 
Frequency 23700000 Hz  36500000 Hz  30100000 Hz 
Ranging Service ID 12560  12560  12560 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 39 dBmV  39 dBmV  40 dBmV 
Upstream Modulation [3] QPSK
[3] 64QAM
[3] QPSK
[3] 64QAM
[3] QPSK
[3] 64QAM
Ranging Status Success  Success  Success 




The modem error logs show a timeline like this right before I see the reset message in the log:

Jan 01 1970 00:00:22 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xxxxx;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot due to T4 timeout ;XXXXX;CM-QOS=1.1;CM-VER=3.0;
Apr 13 2017 15:31:18 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=XXXX;CM-QOS=1.1;CM-VER=3.0;
Apr 13 2017 15:31:18 3-Critical R03.0 Ranging Request Retries exhausted;CM-MAC=XXXX;CM-QOS=1.1;CM-VER=3.0;


We've had a tech out here and he was basically useless. He said he changed some cable ends and said we'd be good to go and 30 minutes later same issue! The weird thing is once we have a connection if we do stuff like stream movies (aka netflix) it'll stay up but once we're done it'll eventually lose connection and the modem will reboot. If I try and run a constant ping I'll see a bunch of timeouts mixed in with good calls and eventually it'll lose DNS (ping to www.google.com is unreachable). Also when things are down our internet phone seems broken too..


Any ideas/help would be appreciated since the comcast guy didn't help us at all today. We called and complained and we're having another tech out in 3 more days!


Thanks in advance.

Frequent Visitor

Re: SB6141 Keeps disconnecting

This makes atleast two of us, within the last few days, reporting the same issue.  I got a SB6141  from Amazon just a week ago, and i have had disconnects and automatic modem reboots.  Yesterday it reached a peak, with nearly 10 disconnects/reboots  by this modem.   So, i got frustrated and searched the net.  I find that this is a common problem that has been reported for past year or two.  And nothing has been done to fix this bug by Arris & comcast working together.    So, i am inclined to think that the technical support is  not  doing their job, in escalation of issues to engineers.


I called into tech support and requested that they make sure that i have the latest firmware.  Other than returning this modem, i am not sure what else i can do.  I got comcast installation done just 10 days ago, and the guy made sure that my signal is good at my home.  Any suggestions ?

Frequent Visitor

Re: SB6141 Keeps disconnecting

Browsing the forum reveals that others who reported this issue in the forum.  How do i make sure that my modem is running the latest firmware available ?  How do i request a push  of  firmware  (once more) into the modem ?   Some more info can be found at this thread  :   SB6141 Frequent disconnect related thread

Frequent Visitor

Re: SB6141 Keeps disconnecting

Reading through  some threads  revealed that i can look at the logs  of my  cablem modem.  I see that the modem  is repeating the following messages  every   hour or two..... (i took out the MAC info in order to post here).  The signal  power is ranging between 1 to 3dBmV.  I can post all the data here if needed, but don't want to clutter for now.   Please advice how i can reach someone who has authorization to look into tech details, rather than speaking to a  phone rep, who pretends to know things.


Time Priority Code Message
Apr 15 2017 06:25:14 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=xxxx;CMTS-MAC=xxxx;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:21 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xxxx;CMTS-MAC=xxxx;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=xxxx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
New Poster

Re: SB6141 Keeps disconnecting


Finally got a service tech who knew networking. They had to track our issue back to the outside cabling. Apparently up the street there was a line issue affecting my upstream sending. So the issue turned out to definitely be a line issue and NOT a modem related issue so all the modem related suggestions wouldn't help fix me at all. Two of the techs we dealt with didn't even know what I was showing him with the logs etc..


Only took 12 days for them to get it working again. If you end up here thinking you have a modem issue make sure you get comcast to send you out a real tech and not a basic 'cable puller' tech. Once we got a real tech, he only had to spend 15 minutes inside our house and was able to say "it's not your modem it's us". Then he was able to start the real problem resolution we needed.