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Cameron0390
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Friday, April 10th, 2026 8:45 PM

CM3000 Signal Distress: High Upstream Power (52dBmV) and Excessive Uncorrectables on OFDM. Multiple T3 Timeouts.

I am seeking a technician visit to investigate a likely "outside plant" or "drop" issue. I am using a Netgear CM3000 on the Next Generation (Mid-Split) network.

The Issue: Severe OBS dropped frames and latency spikes, resulting in very unstable streaming quality and in-game performance issues. My modem LEDs are also randomly turning off/on.  Other CM3000 users have mentioned issues with the LED indicators.  Could be related to problems with the latest firmware version V6.01.04.

Current Signal Levels (Direct to Wall):

  • Upstream Power: 50.5 – 52.3 dBmV (Hitting the ceiling)
  • Downstream OFDM Power: -9.32 to -12.12 dBmV (Very low)
  • SNR/MER: 36.5 dB on OFDM channels
Log Summary:
Consistent T3 Timeouts, Dynamic Range Window (DRW) violations, and constant CM-STATUS 16/24 flapping on Channel 194.
Request:  Based on the "Commanded Power Exceeds Value" errors, I would like the tap/drop inspected for ingress or a bad connector.
Technical Summary for Support:
  • High Power/Low Lock: Only 4 Upstream SC-QAM channels locked, with Channel 1 hitting 52.3 dBmV.
  • OFDM Failure: Downstream Channel 194 is showing 24,789 Uncorrectables with an SNR of only 36.5 dB and power at -12.22 dBmV.
  • Signal Tilt: There is a 5.5 dBmV drop between the standard frequencies and the high-end OFDM carrier (957 MHz), indicating significant cable attenuation or a failing drop.

Quick Edit: The modem has 'Extended Upstream Transmit Power' enabled just to maintain a lock, yet it is still hitting 52.3 dBmV. This suggests the return path attenuation is well beyond normal limits.

Cable logs are as follows:

Fri Apr 10 11:53:16 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 4; Chan ID: 28 36 39 40 41 42 43 44; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-CM-QOS=1.1;CM-VER=3.1;
Fri Apr 10 11:53:00 2026 (Warning (5))  MDD message timeout;CM-CM-QOS=1.1;CM-VER=3.1;
Fri Apr 10 00:48:40 2026 (Critical (3))  Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-CM-QOS=1.1;CM-VER=3.1;
Fri Apr 10 00:32:18 2026 (Warning (5))  Dynamic Range Window violation
Fri Apr 10 00:32:18 2026 (Warning (5))  RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-CM-QOS=1.1;CM-VER=3.1;
Fri Apr 10 00:32:18 2026 (Warning (5))  Dynamic Range Window violation
Fri Apr 10 00:32:18 2026 (Warning (5))  RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-CM-QOS=1.1;CM-VER=3.1;
Fri Apr 10 00:32:16 2026 (Critical (3))  Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 20:26:33 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 20:20:20 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 19:51:17 2026 (Critical (3))  Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 19:35:52 2026 (Notice (6))  US profile assignment change. US Chan ID: 41; Previous Profile: 11 13; New Profile: 12 13.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 19:29:07 2026 (Notice (6))  US profile assignment change. US Chan ID: 41; Previous Profile: 12 13; New Profile: 11 13.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 19:23:27 2026 (Critical (3))  Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 19:08:01 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 18:58:12 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 18:54:15 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 18:41:39 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 18:40:23 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 18:35:42 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 17:56:29 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 17:51:45 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 17:50:22 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 17:41:47 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 17:28:56 2026 (Critical (3))  Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 17:04:19 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 16:57:32 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 16:57:23 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 16:50:38 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 16:48:26 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 16:15:45 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 15:49:04 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 15:34:15 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 15:29:19 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 15:24:09 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 15:12:22 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 15:00:21 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 14:52:50 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;
Thu Apr 09 14:48:31 2026 (Notice (6))  CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-CM-QOS=1.1;CM-VER=3.1;

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 20 477000000 Hz -6.8 dBmV 41.3 dB 5 0
2 Locked QAM256 13 435000000 Hz -6.7 dBmV 41.7 dB 37 0
3 Locked QAM256 14 441000000 Hz -6.7 dBmV 41.6 dB 50 0
4 Locked QAM256 15 447000000 Hz -6.7 dBmV 41.5 dB 27 0
5 Locked QAM256 16 453000000 Hz -6.8 dBmV 41.5 dB 29 0
6 Locked QAM256 17 459000000 Hz -6.8 dBmV 41.4 dB 23 0
7 Locked QAM256 18 465000000 Hz -6.8 dBmV 41.4 dB 26 0
8 Locked QAM256 19 471000000 Hz -6.8 dBmV 41.4 dB 22 0
9 Locked QAM256 21 483000000 Hz -6.7 dBmV 41.4 dB 11 0
10 Locked QAM256 22 489000000 Hz -6.8 dBmV 41.4 dB 4 0
11 Locked QAM256 23 495000000 Hz -6.7 dBmV 41.4 dB 9 0
12 Locked QAM256 24 501000000 Hz -6.9 dBmV 41.3 dB 3 0
13 Locked QAM256 25 507000000 Hz -7.0 dBmV 41.2 dB 4 0
14 Locked QAM256 26 513000000 Hz -7.1 dBmV 41.2 dB 3 0
15 Locked QAM256 27 519000000 Hz -7.3 dBmV 40.8 dB 2 0
16 Locked QAM256 28 525000000 Hz -7.5 dBmV 40.7 dB 3 0
17 Locked QAM256 29 531000000 Hz -7.7 dBmV 40.4 dB 4 0
18 Locked QAM256 30 537000000 Hz -7.9 dBmV 40.3 dB 2 0
19 Locked QAM256 31 543000000 Hz -8.0 dBmV 40.2 dB 3 0
20 Locked QAM256 32 549000000 Hz -8.1 dBmV 40.1 dB 3 0
21 Locked QAM256 33 555000000 Hz -8.3 dBmV 40.0 dB 8 0
22 Locked QAM256 34 561000000 Hz -8.5 dBmV 39.9 dB 8 0
23 Locked QAM256 35 567000000 Hz -8.5 dBmV 39.9 dB 8 0
24 Locked QAM256 36 573000000 Hz -8.6 dBmV 39.9 dB 6 0
25 Locked QAM256 37 579000000 Hz -8.5 dBmV 40.0 dB 4 0
26 Locked QAM256 38 585000000 Hz -8.4 dBmV 40.1 dB 3 0
27 Locked QAM256 39 591000000 Hz -8.4 dBmV 40.2 dB 2 0
28 Locked QAM256 40 597000000 Hz -8.4 dBmV 40.2 dB 9 0
29 Locked QAM256 41 603000000 Hz -8.4 dBmV 40.2 dB 18 0
30 Locked QAM256 42 609000000 Hz -8.3 dBmV 40.2 dB 11 0
31 Locked QAM256 43 615000000 Hz -8.3 dBmV 40.2 dB 11 0
32 Locked QAM256 44 621000000 Hz -8.4 dBmV 39.9 dB 11 0
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 1 5120 Ksym/sec 16400000 Hz 52.3 dBmV
2 Locked ATDMA 2 5120 Ksym/sec 22800000 Hz 51.5 dBmV
3 Locked ATDMA 3 5120 Ksym/sec 29200000 Hz 50.3 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 35600000 Hz 50.5 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 ,2 ,1 ,3 193 722000000 Hz -9.22 dBmV 39.0 dB 208 ~ 3887 863549626 858653252 68
2 Locked 0 ,2 ,1 ,3 194 957000000 Hz -12.22 dBmV 36.5 dB 148 ~ 3947 872072880 803969253 24789
 
Upstream OFDMA Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Locked 12 ,13 41 36200000 Hz 45.0 dBmV
2 Not Locked 0 0 0 Hz 0 dBmV

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