I have been having issues with my modem reseting several times a day. Here is my system log and power levels. I had a comcast technician come out today and tell me that my modem is "bad" and I need to replace it. I bought this modem 2 years ago, it should be fine.
| Time |
Priority |
Description |
| 2021-09-07, 11:21:20 |
Notice (6) |
DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1; |
| Time Not Established |
Notice (6) |
Honoring MDD; IP provisioning mode = IPv6 |
| Time Not Established |
Critical (3) |
No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];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=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; |
| Time Not Established |
Critical (3) |
No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];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=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; |
|
|
|
|
Apply Cancel
|
| Frequency start Value |
| This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect. |
|
|
|
| <tabindex=-1>Startup Procedure</tabindex=-1> |
| Procedure |
Status |
Comment |
| Acquire Downstream Channel |
519000000 Hz |
Locked |
| Connectivity State |
OK |
Operational |
| Boot State |
OK |
Operational |
| Security |
Enable |
BPI+ |
| IP Provisioning Mode |
Honor MDD |
IPv6 only |
|
|
| <tabindex=-1>Downstream Bonded Channels</tabindex=-1> |
| Channel |
Lock Status |
Modulation |
Channel ID |
Frequency |
Power |
SNR / MER |
Unerrored Codewords |
Correctable Codewords |
Uncorrectable Codewords |
| 1 |
Locked |
QAM256 |
20 |
519000000 Hz |
3.0 dBmV |
42.5 dB |
27510261 |
0 |
0 |
| 2 |
Locked |
QAM256 |
4 |
417000000 Hz |
2.6 dBmV |
42.6 dB |
26261645 |
0 |
0 |
| 3 |
Locked |
QAM256 |
5 |
423000000 Hz |
2.8 dBmV |
42.5 dB |
26265212 |
0 |
0 |
| 4 |
Locked |
QAM256 |
6 |
429000000 Hz |
3.0 dBmV |
42.8 dB |
26268818 |
0 |
0 |
| 5 |
Locked |
QAM256 |
7 |
435000000 Hz |
3.3 dBmV |
42.8 dB |
26272711 |
0 |
0 |
| 6 |
Locked |
QAM256 |
8 |
441000000 Hz |
3.3 dBmV |
42.7 dB |
26276478 |
0 |
0 |
| 7 |
Locked |
QAM256 |
9 |
447000000 Hz |
3.3 dBmV |
42.7 dB |
26279572 |
0 |
0 |
| 8 |
Locked |
QAM256 |
10 |
453000000 Hz |
3.1 dBmV |
42.6 dB |
26283931 |
0 |
0 |
| 9 |
Locked |
QAM256 |
11 |
459000000 Hz |
3.0 dBmV |
42.5 dB |
26287975 |
0 |
0 |
| 10 |
Locked |
QAM256 |
12 |
465000000 Hz |
3.1 dBmV |
42.4 dB |
26291202 |
0 |
0 |
| 11 |
Locked |
QAM256 |
13 |
471000000 Hz |
3.4 dBmV |
42.6 dB |
26295005 |
0 |
0 |
| 12 |
Locked |
QAM256 |
14 |
477000000 Hz |
3.6 dBmV |
42.3 dB |
26299420 |
0 |
0 |
| 13 |
Locked |
QAM256 |
15 |
483000000 Hz |
3.6 dBmV |
42.6 dB |
26303224 |
0 |
0 |
| 14 |
Locked |
QAM256 |
16 |
489000000 Hz |
3.6 dBmV |
42.6 dB |
26306650 |
0 |
0 |
| 15 |
Locked |
QAM256 |
17 |
495000000 Hz |
3.6 dBmV |
42.6 dB |
26310092 |
0 |
0 |
| 16 |
Locked |
QAM256 |
18 |
507000000 Hz |
2.9 dBmV |
42.4 dB |
26314587 |
0 |
0 |
| 17 |
Locked |
QAM256 |
19 |
513000000 Hz |
2.5 dBmV |
42.2 dB |
26320925 |
0 |
0 |
| 18 |
Locked |
QAM256 |
21 |
525000000 Hz |
3.2 dBmV |
42.5 dB |
26324112 |
0 |
0 |
| 19 |
Locked |
QAM256 |
22 |
531000000 Hz |
3.5 dBmV |
42.7 dB |
26327815 |
0 |
0 |
| 20 |
Locked |
QAM256 |
23 |
537000000 Hz |
3.5 dBmV |
42.7 dB |
26332069 |
0 |
0 |
| 21 |
Locked |
QAM256 |
24 |
543000000 Hz |
3.6 dBmV |
42.8 dB |
26335819 |
0 |
0 |
| 22 |
Locked |
QAM256 |
25 |
549000000 Hz |
3.6 dBmV |
42.7 dB |
26339112 |
0 |
0 |
| 23 |
Locked |
QAM256 |
26 |
555000000 Hz |
3.6 dBmV |
42.6 dB |
26343133 |
11 |
0 |
| 24 |
Locked |
QAM256 |
27 |
561000000 Hz |
3.8 dBmV |
42.6 dB |
26346849 |
0 |
0 |
| 25 |
Locked |
QAM256 |
28 |
567000000 Hz |
4.1 dBmV |
42.7 dB |
26350412 |
0 |
0 |
| 26 |
Locked |
QAM256 |
29 |
573000000 Hz |
4.1 dBmV |
42.8 dB |
26353842 |
17 |
0 |
| 27 |
Locked |
QAM256 |
30 |
579000000 Hz |
3.9 dBmV |
42.4 dB |
26357647 |
8 |
0 |
| 28 |
Locked |
QAM256 |
31 |
585000000 Hz |
3.9 dBmV |
41.2 dB |
26361567 |
6 |
0 |
| 29 |
Locked |
QAM256 |
32 |
591000000 Hz |
3.9 dBmV |
42.3 dB |
26365310 |
0 |
0 |
| 30 |
Locked |
QAM256 |
33 |
597000000 Hz |
4.1 dBmV |
42.2 dB |
26366450 |
25 |
0 |
| 31 |
Locked |
QAM256 |
34 |
603000000 Hz |
4.1 dBmV |
41.6 dB |
26365669 |
0 |
0 |
| 32 |
Not Locked |
Unknown |
0 |
0 Hz |
0.0 dBmV |
0.0 dB |
0 |
0 |
0 |
|
|
| <tabindex=-1>Upstream Bonded Channels</tabindex=-1> |
| Channel |
Lock Status |
Modulation |
Channel ID |
Frequency |
Power |
| 1 |
Locked |
ATDMA |
61 |
16400000 Hz |
45.0 dBmV |
| 2 |
Locked |
ATDMA |
62 |
22800000 Hz |
45.0 dBmV |
| 3 |
Locked |
ATDMA |
63 |
29200000 Hz |
45.0 dBmV |
| 4 |
Locked |
ATDMA |
64 |
35600000 Hz |
43.8 dBmV |
| 5 |
Not Locked |
Unknown |
0 |
0 Hz |
0.0 dBmV |
| 6 |
Not Locked |
Unknown |
0 |
0 Hz |
0.0 dBmV |
| 7 |
Not Locked |
Unknown |
0 |
0 Hz |
0.0 dBmV |
| 8 |
Not Locked |
Unknown |
0 |
0 Hz |
0.0 dBmV |
|
|
| <tabindex=-1>Downstream OFDM Channels</tabindex=-1> |
| Channel |
Lock Status |
Modulation / Profile ID |
Channel ID |
Frequency |
Power |
SNR / MER |
Active Subcarrier Number Range |
Unerrored Codewords |
Correctable Codewords |
Uncorrectable Codewords |
| 1 |
Locked |
0, 1, 2, 3 |
48 |
722000000 Hz |
2.8 dBmV |
39.5 dB |
1228 ~ 2867 |
14503025 |
5399595 |
333 |
| 2 |
Not Locked |
0 |
0 |
0 Hz |
3.5 dBmV |
0.0 dB |
0 ~ 4095 |
0 |
0 |
0 |
|
|
| <tabindex=-1>Upstream OFDMA Channels</tabindex=-1> |
| Channel |
Lock Status |
Modulation / Profile ID |
Channel ID |
Frequency |
Power |
| 1 |
Not Locked |
Unknown |
0 |
0 Hz |
0 dBmV |
| 2 |
Not Locked |
Unknown |
0 |
0 Hz |
0 dBmV |
|
|
| Current System Time: Tue Sep 07 11:31:02 2021 |
| System Up Time: 0:10:26 |
EG
Expert
•
118.3K Messages
5 years ago
The signal stats figures are 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 figures 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 to see whether or not everything is in the green zone, see your node / cable plant and modem health, and also see a history plot for the modem. You should get a reply here in your topic. Good luck !
Even though the signal stats looked o/k at that snapshot in time, the error log entries confirm 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 figures 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 can check the CMTS (Cable Modem Termination System) 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 !
0
0
kurtn
Visitor
•
2 Messages
5 years ago
All of my power levels appear to be in spec, but upstream is a bit high. I read that the max recommended upstream power is 49dB. Could this be the issue? I have noted that when I run a speed test, sometimes it will cause the modem to reset (all lights go out and start flashing one by one, top to bottom until they are all steady lit again).
1
0
XfinityMary
Official Employee
•
271 Messages
5 years ago
Thank you @EG for bringing this connection concern to our attention!
@kurtn, I am sorry to hear that you are experiencing some T3 timeout issue. I know it is important to make sure you have a stable and reliable connection. I understand you mentioned that a technician was recently out and mentioned the issue could be from your modem. One way to test this it by trying out a different modem to see if this resolves the issue. While an on-site technician would be able to provide you with the best recommendation, I would be more than happy to review your signals and connection. Can you please send us a Private Chat Message with your full service address along with your first and last name? We look forward to assisting!
To send us a Private Chat Message, select the message icon in the top right corner and then search for Xfinity support. With our new Xfinity support chat, you do not need to input the name of a person. Just select Xfinity support and you will be able to speak with the next available specialist.
**EDITED TO CORRECT TAGGED USERNAME
(edited)
0