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user_zqts3p
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Saturday, December 16th, 2023 7:01 AM

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Netgear CM2000 modem downstream light blinking and status "BAD"

I got Gigabit internet, since a week ago, the download speed fluctuates a lot, sometimes only 0.2 mbps, sometimes 50 mbps, I found that the Netgear CM2000 modem downstream light keep blinking,  Here is the Netgear CM2000 log, any help is greatly appreciated.

Cable Connection
Cancel Apply
Cable Diagnostic
Status:   Poor
Action:  
[Partial Service]
If the Partial Service mode does not go away within a few hours (Click the Refresh button after each step):
1) Make sure the coaxial cable is tightly connected.
2) Remove any unnecessary splitters.
3) Replace any required ones.
4) Contact your service provider for troubleshooting help.
[Downstream Power Level/Downstream SNR]
Try these actions (Click the Refresh button after each step):
1) Make sure the coaxial cable is tightly connected.
2) Remove any unnecessary splitters.
3) Replace any required splitters.
4) Contact your service provider for troubleshooting help.
CM Status:
Downstream Status:
Upstream Status:
  Refresh Save Cable Diagnostic Info
 
Advanced Information
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.
Starting Frequency
 
Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 579000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enabled BPI+
IP Provisioning Mode Honor MDD IPv6 only
 
Downstream Bonded Channels (Partial Service)
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 28 579000000 Hz -12.6 dBmV 37.4 dB 2 0
2 Locked QAM256 13 489000000 Hz -9.0 dBmV 40.0 dB 0 0
3 Locked QAM256 14 495000000 Hz -9.4 dBmV 39.8 dB 0 0
4 Locked QAM256 15 501000000 Hz -9.5 dBmV 39.7 dB 0 0
5 Locked QAM256 16 507000000 Hz -9.5 dBmV 39.8 dB 0 0
6 Locked QAM256 17 513000000 Hz -9.6 dBmV 38.6 dB 0 0
7 Locked QAM256 18 519000000 Hz -9.9 dBmV 39.2 dB 0 0
8 Locked QAM256 19 525000000 Hz -10.3 dBmV 39.4 dB 0 0
9 Locked QAM256 20 531000000 Hz -10.6 dBmV 39.1 dB 0 0
10 Locked QAM256 21 537000000 Hz -10.9 dBmV 39.0 dB 2 0
11 Locked QAM256 22 543000000 Hz -11.1 dBmV 38.8 dB 0 0
12 Locked QAM256 23 549000000 Hz -11.4 dBmV 38.6 dB 2 0
13 Locked QAM256 24 555000000 Hz -11.7 dBmV 38.3 dB 2 0
14 Locked QAM256 25 561000000 Hz -11.9 dBmV 38.2 dB 1 0
15 Locked QAM256 26 567000000 Hz -12.0 dBmV 37.9 dB 0 0
16 Locked QAM256 27 573000000 Hz -12.3 dBmV 37.7 dB 2 0
17 Locked QAM256 29 585000000 Hz -13.1 dBmV 36.8 dB 0 0
18 Locked QAM256 30 591000000 Hz -13.7 dBmV 36.3 dB 0 0
19 Locked QAM256 31 597000000 Hz -14.2 dBmV 35.9 dB 0 0
20 Locked QAM256 32 603000000 Hz -14.4 dBmV 35.7 dB 1 0
21 Locked QAM256 33 609000000 Hz -14.5 dBmV 35.7 dB 2 0
22 Locked QAM256 34 615000000 Hz -15.0 dBmV 35.2 dB 2 0
23 Locked QAM256 35 621000000 Hz -15.6 dBmV 34.5 dB 0 0
24 Locked QAM256 36 627000000 Hz -16.1 dBmV 33.9 dB 1 0
25 Locked QAM256 37 633000000 Hz -16.7 dBmV 33.3 dB 3 0
26 Locked QAM256 38 639000000 Hz -17.2 dBmV 32.9 dB 5 0
27 Locked QAM256 39 645000000 Hz -17.7 dBmV 32.4 dB 4 0
28 Locked QAM256 40 651000000 Hz -18.6 dBmV 31.6 dB 9 0
29 Locked QAM256 41 657000000 Hz -19.2 dBmV 31.0 dB 18 0
30 Locked QAM256 42 663000000 Hz -19.6 dBmV 30.6 dB 135 0
31 Locked QAM256 43 669000000 Hz -20.2 dBmV 30.0 dB 1008 0
32 Locked QAM256 44 675000000 Hz -20.5 dBmV 28.4 dB 13796351 1512362
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 19 5120 Ksym/sec 29200000 Hz 38.3 dBmV
2 Locked ATDMA 18 5120 Ksym/sec 22800000 Hz 38.0 dBmV
3 Locked ATDMA 17 5120 Ksym/sec 16400000 Hz 38.0 dBmV
4 Locked ATDMA 20 5120 Ksym/sec 35600000 Hz 38.3 dBmV
5 Not Locked Unknown 0 0 0 0.0 dBmV
6 Not Locked Unknown 0 0 0 0.0 dBmV
7 Not Locked Unknown 0 0 0 0.0 dBmV
8 Not Locked Unknown 0 0 0 0.0 dBmV
 
Downstream OFDM Channels
Channel Lock Status Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier
Number Range		 Unerrored
Codewords		 Correctable
Codewords		 Uncorrectable
Codewords
1 Locked 0 ,1 ,2 ,3 193 957000000 Hz -32.22 dBmV 18.2 dB 148 ~ 3947 36821559 1774793 35046766
2 Not Locked 0 0 0 Hz 0 dBmV 0 dB 0 ~ 4095 0 0 0
 
Upstream OFDMA Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked 0 0 0 Hz 0 dBmV
2 Not Locked 0 0 0 Hz 0 dBmV
 
Extended Upstream Transmit Power
 
Current System Time:Fri Dec 15 22:51:39 2023
System Up Time:00:45:29

Question

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Updated 

1 year ago

391

2

0

user_zqts3p

2 Messages

1 year ago

Here is the event log:

Event Log
Clear Log Refresh Export
 
Time Priority Description
Sat Dec 16 00:00:30 2023 (Notice (6)) CM-STATUS message sent. Event Type Code: 4; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sat Dec 16 00:00:06 2023 (Warning (5)) MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:56:05 2023 (Notice (6)) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:55:59 2023 (Notice (6)) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:55:53 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:55:51 2023 (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;
Fri Dec 15 23:45:51 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:35:51 2023 (Notice (6)) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:35:44 2023 (Notice (6)) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:35:35 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:35:33 2023 (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;
Fri Dec 15 23:25:32 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:15:32 2023 (Notice (6)) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:15:25 2023 (Notice (6)) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:15:15 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:15:07 2023 (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;
Fri Dec 15 23:15:01 2023 (Notice (6)) TLV-11 - unrecognized OID;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:14:53 2023 (Notice (6)) Honoring MDD; IP provisioning mode = IPv6
Fri Dec 15 23:14:50 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 23:14:44 2023 (Warning (5)) ToD request sent - No Response received;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)) 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;
Fri Dec 15 22:07:23 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 22:06:56 2023 (Critical (3)) UCD invalid or channel unusable;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;
Fri Dec 15 21:43:45 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 21:43:19 2023 (Critical (3)) UCD invalid or channel unusable;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;
Fri Dec 15 21:40:16 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 21:40:16 2023 (Critical (3)) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 21:40:13 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 21:31:34 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 21:31:08 2023 (Critical (3)) UCD invalid or channel unusable;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;
Fri Dec 15 20:34:06 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Dec 15 20:33:39 2023 (Critical (3)) UCD invalid or channel unusable;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;
Thu Dec 14 20:16:08 2023 (Critical (3)) UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Dec 14 20:15:41 2023 (Critical (3)) UCD invalid or channel unusable;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;

(edited)

2

0

EG

Expert

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110.4K Messages

@user_zqts3p​ 

Please redact all of the CM MAC and the CMTS MAC addresses from your second post of the error log entries for your privacy. They are considered to be personal information. The posting of personally identifiable information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically. It flagged your post as "Private".

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick

1 year ago

0

ccRuben

Retired Employee

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729 Messages

@user_zqts3p We will be happy to help with your connection concerns. Please send a direc message to get started. Thank you 

1 year ago

0

flatlander3

Problem Solver

 • 

1.5K Messages

1 year ago

Well that's true.  Downstream power is out of spec.  Should be -7 to +7 dBmV (in a perfect world that doesn't happen it would be 0dBmV), and SNR (signal to noise) really does need to be over 35dB.  OFDM uncorrectables are never good and signal is really low there.  It's a mess there. 

 If you want to look at it yourself, take a look here:    https://forums.xfinity.com/conversations/your-home-network/internet-troubleshooting-tips/602dae4ac5375f08cde52ea0  Splitters/bad cable/bad connectors.  A powered amp perhaps that isn't plugged in if you have one, etc.  If you can get to were the service enters the residence from the street, bypass your house wiring entirely for a test and try the coax there.  Then you'll know if there is anything you can do about it, or if that's what it looks like coming in from the street.  

You could try doing a "factory default" reset on the CM2000 if something got wrapped around the axle with a firmware/config file push, but the signal you are seeing is pretty ugly.  That's probably not going to be it.   

(edited)

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