High number of uncorrectable cable modem errors on all downstream channels

I have been having continuous uncorrectable cable modem errors since early March on all 31 downstream QAM256 channels and the single downstream OFDM channel. The errors include CM-STATUS Type Code 1, 2, 4, 5, 16, 24 messages, MDD message timeouts and Started Unicast Maintenance Ranging - No Response received - T3 time-out. I believe this indicates there is a lot noise on the downstream channels.

The number of uncorrectable errors are much higher at night, peaking around 9pm to 3am local time with continuous errors. During the day the errors are more random. These uncorrectable cable modem errors are causing drop-outs and buffering issues when streaming movies and doing video conferences.

As seen by the cable modem log (see the bottom of my post) from last night the downstream and upstream power levels are very good.

There has been three Xfinity service calls to resolve these issues over the past three weeks, without success.

Visit 1 (4/21) – Xfinity technician (contractor) performed initial troubleshooting. The technician discovered that the cable drop from the pole to my house had been severely chewed by tree squirrels. The technician replaced the drop. He was not able to reach the 4-way tap on the main cable so he had to use a short piece of the original cable to couple into the new drop. The technician said that all signal levels looked good. The uncorrectable cable modem errors returned within two hours after the technician left. That night the number of uncorrectable errors was nearly as bad as before the drop was replaced.

Visit 2 (4/23) – Xfinity technician (employee) – The technician continued to troubleshoot the issue. The technician replaced the 3-way splitter in the junction box on the outside of my house with a new 2-way splitter and put new connectors on the two coax cables going inside the house (cable modem and TiVo Roamio box). The technician checked all the signal levels. Inside the house, the technician replaced the coax connector on the line going to my Netgear CM1000 modem that has been in service for over 8 years. (Note – the coax cable for the modem is a continuous length of RG6 that connects to the 2-way splitter in the outside junction box. There are no other splitters or couplers in this path.) The technician checked the signal at the end of the modem end of the cable and said that the signal levels were good. The technician recommended that I should consider replacing the CM1000 model with a new model.

I purchased and installed a new Netgear CM3000 (FW V5.01.02) cable modem on 4/24. The CM3000 is seeing the same errors as my 8-year old CM1000.

Visit 3 (4/30) - Xfinity technician (employee) – Same technician as the previous visit on 4/23. The technician used a ladder to climb the pole to inspect the 4-way tap on the main cable. There was some corrosion on the tap connector. The technician removed the short length of the original cable (see Visit 1). The technician moved my drop to another connector on the 4-way tap that was not being used. This connector had no corrosion. The technician said that all signal levels looked good. The technician said that if the cable modem errors continue then the issue is probably due to a cable plant problem or a problem with the local node. The technician texted me his contact information and told me to monitor the errors and text me in the next few days. If the errors continue the technician said that he will work with Network Operations to resolve the issue.

I texted the technician on 5/2 and stated that the errors have continued and asked him with is the next step. I received no reply from the technician. I tried texting him twice more and left him a voicemail. I received no reply.

I’m not sure how to proceed. I don’t want to schedule a fourth repair visit with a new technician, especially since the issue is probably a cable plant or local node problem. Any help would be appreciated.

Cable Diagnostic  Netgear CM3000 FW V5.01.02

Status: Good

CM Status: Good

Downstream Status: Good

    Downstream Power Level: Good

    Downstream SNR Level: Good

Upstream Status: Good

    Upstream Power Level: Good

Current Time: Mon May 12 02:58:49 2025

System Up Time:2 days 23:36:12

Startup Procedure
Acquire Downstream Channel: 405000000 Hz  Locked
Connectivity State:          OK       Operational
Boot State:                  OK       Operational
Security:                   Enabled   BPI+
IP Provisioning Mode:       Honor MDD   IPv6 only

Downstream Bonded Channels
Channel LockedStatus Modulation ChannelID  Frequency     Power    SNR   Correctables Uncorrectables     
      1     Locked     QAM256      4     405000000 Hz     2.3     40.5     4984     7349
      2     Locked     QAM256      5     411000000 Hz     2.9     40.8     9462621     8031975
      3     Locked     QAM256      6     417000000 Hz     3.5     41.1     3052061     350006
      4     Locked     QAM256      7     423000000 Hz     3     40.8     14669     20408
      5     Locked     QAM256      8     429000000 Hz     2.5     40.5     20030     22516
      6     Locked     QAM256      9     435000000 Hz     2.4     40.5     25988     27341
      7     Locked     QAM256     10     441000000 Hz     2.3     40.6     26577     25079
      8     Locked     QAM256     11     447000000 Hz     2.4     40.7     29551     28954
      9     Locked     QAM256     12     453000000 Hz     2     40.3     955251     1413936
     10     Locked     QAM256     13     459000000 Hz     1.7     39.9     108047     249755
     11     Locked     QAM256     14     465000000 Hz     1.8     40     108361     108274
     12     Locked     QAM256     15     471000000 Hz     2.4     40.3     307129     240885
     13     Locked     QAM256     16     477000000 Hz     2.6     40.4     316124     250875
     14     Locked     QAM256     17     483000000 Hz     2.5     40.2     85683     106022
     15     Locked     QAM256     18     489000000 Hz     2.4     40     282814     159669
     16     Locked     QAM256     19     495000000 Hz     2.4     40.2     85997     74439
     17     Locked     QAM256     20     507000000 Hz     2.6     40.3     124083     251087
     18     Locked     QAM256     21     513000000 Hz     2     40     139198     322339
     19     Locked     QAM256     22     519000000 Hz     1.6     39.7     122062     231605
     20     Locked     QAM256     23     525000000 Hz     1.5     39.7     105149     171163
     21     Locked     QAM256     24     531000000 Hz     2     40.1     125795     434758
     22     Locked     QAM256     25     537000000 Hz     2     40.1     313293     515915
     23     Locked     QAM256     26     543000000 Hz     2.1     39.8     345617     604659
     24     Locked     QAM256     27     549000000 Hz     2.2     39.6     375919     817343
     25     Locked     QAM256     28     555000000 Hz     2.7     39.7     424629     930990
     26     Locked     QAM256     29     561000000 Hz     3.4     40.1     748528     1436744
     27     Locked     QAM256     30     567000000 Hz     3.5     40.1     2480207     5234271
     28     Locked     QAM256     31     573000000 Hz     3.1     39.7     4410467     4413114
     29     Locked     QAM256     32     579000000 Hz     3     39.6     9979271     8038751
     30     Locked     QAM256     33     585000000 Hz     3.2     39.8     10385682     5542438
     31     Locked     QAM256     34     591000000 Hz     3.4     40.1     16847133     1469187
     32     Not Locked     Unknown      0     0 Hz     0.0     0.0     0     0

Upstream Bonded Channels
Channel   LockedStatus  ChannelType ChannelID   SymbolRate        Frequency       Power     
      1       Locked       ATDMA     96       5120 Ksym/sec       35600000 Hz       46.5 dBmV
      2       Locked       ATDMA     93       5120 Ksym/sec       16400000 Hz       46.0 dBmV
      3       Locked       ATDMA     94       5120 Ksym/sec       22800000 Hz       46.0 dBmV
      4       Locked       ATDMA     95       5120 Ksym/sec       29200000 Hz       46.0 dBmV
      5       Not Locked       Unknown      0       0       0       0.0
      6       Not Locked       Unknown      0       0       0       0.0
      7       Not Locked       Unknown      0       0       0       0.0
      8       Not Locked       Unknown      0       0       0       0.0

Downstream OFDM Channels
Channel   LockedStatus  ProfileID  ChannelID    Frequency       Power       SNR/MER    ActiveSubcarrier    Unerror    Correctable   Uncorrectable
      1     Locked     0 ,1 ,2 ,3     48     850000000 Hz     4.68 dBmV     38.4 dB     1108 ~ 2987     3937861268     3726701261     32461444
      2     Not Locked     0      0     0 Hz     0 dBmV     0 dB     0 ~ 4095     0     0     0

Upstream OFDMA Channels
Channel   LockedStatus    ProfileID    ChannelID    Frequency       Power
      1     Not Locked     0      0     0 Hz     0 dBmV
      2     Not Locked     0      0     0 Hz     0 dBmV

Event Log
         Time               Priority     Description
Mon May 12 02:03:01 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Mon May 12 02:00:46 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Mon May 12 01:33:57 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Mon May 12 01:28:44 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Mon May 12 01:20:17 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Mon May 12 01:10:05 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Mon May 12 01:07:13 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Mon May 12 01:05:20 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 4; Chan ID: 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 48; 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;
Mon May 12 01:05:10 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 5; Chan ID: 4 5 6 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; 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;
Mon May 12 01:05:04 2025     Warning (5)     MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Mon May 12 01:03:31 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 4; Chan ID: 5 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=54:07:7d:c8:2d:a8;CMTS-MAC=00:01:5c:63:f8:75;CM-QOS=1.1;CM-VER=3.1;
Mon May 12 01:03:18 2025     Warning (5)     MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Mon May 12 01:03:15 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; 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;
Mon May 12 00:15:32 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Mon May 12 00:12:31 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 5; Chan ID: 4 5 6 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; 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;
Mon May 12 00:12:22 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 23:55:09 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Sun May 11 23:50:42 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 23:44:53 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Sun May 11 23:38:40 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:41:35 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Sun May 11 22:37:40 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:34:49 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Sun May 11 22:33:32 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:32:59 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:30:59 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 4; Chan ID: 5 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 48; 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;
Sun May 11 22:30:51 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 5; Chan ID: 4 5 6 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:01:5c:63:f8:75;CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:30:46 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 1; Chan ID: 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29; 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;
Sun May 11 22:30:46 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 2; Chan ID: 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:01:5c:63:f8:75;CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:30:45 2025     Warning (5)     MDD message timeout;CM-MAC=54:07:7d:c8:2d:a8;CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:30:38 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; 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;
Sun May 11 22:29:59 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 5; Chan ID: 4 5 6 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:01:5c:63:f8:75;CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:06:08 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Sun May 11 22:05:28 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:02:16 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:02:13 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 22:00:09 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; 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;
Sun May 11 22:00:07 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 21:57:53 2025     Notice (6)     CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sun May 11 21:25:37 2025     Critical (3)     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:01:5c:63:f8:75;CM-QOS=1.1;CM-VER=3.1;