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Uncorrectable Errors - Tech Questions
Few months ago I had issues with games randomly disconnecting. This started to happen after a wind storm that came through the area. I noticed DS OFDM channels had Uncorrectables. So I checked all my...
It was a Cox tech and he also was a contractor. Woke up today and now my modem randomly has only the Lan lights on and rest of the lights are off. Power cycling fixes the issue. I've had to power cycle it 2 times today because of it. The power readings look the same. I'm wondering if the high power signal is causing this issue? Like the modem is going into protection mode when the power levels get too high? I did call Cox last night about the tech taking the filter but all the rep could do is submit a request to bring it back. I called them today and was told I will need a tech to come out again to address the modem having this issue. I told them it's most likely caused by the tech taking the filter when a previous tech said it was needed. I factory reset the modem to see if that helps. The Tech support rep tried to refer me to Netgear customer service. I said "The power levels are out of spec and the issue is not having the filter." She then said "I could contact them and see if there's an update needed for the modem or I could do it myself." I told her there's no option in the modem settings to do so. She said "The Genie has that option." I told her it's not there and it was there before when I first got the modem, and I updated it, but the option went away. She said "Well we can do it on our end because it's not our equipment." I used to work at cox tier 1 tech support and we were able to before, I guess they got rid of that option? I once again forgot to take a screenshot of the logs. I will for sure again. I'm worried if my modem is dying or if it's not that? I do have an old CM1000v2 I could swap in, but rather be sure this fairly new CM1200 is bad or not. I'm greatfull of your feedback and all this random things happening! Here's once again my readings...
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The CM1200 does not now, nor has it ever had the option for the end user to update the firmware. It is the same as the other CM series modems. ISP firmware updates only.
In your current set of readings, Your power levels are still high, and I note you no longer have a second upstream OFDMA channel locked at 918 MHz. In your other posts, you had that second channel locked.
We may have a terminology issue. I use a 3 dB attenuator to lower my power levels. It has no filtering. You are calling yours a filter. Sometimes it is called an attenuator pad.
This brand of attenuator comes in 3 dB and 8 dB sizes for around $5. Links to Amazon.
I think your mistaken on the Upstream OFDMA. I'm not seeing what your seeing on previous shared screenshots/readings.
Yes, I'm speaking of a attenuator. The thing that screws on between two coax cables. It lowered my power levels. It was recommended by a friend. I asked a previous tech for it. Which he gave it to me with no issues.
Thanks for the links!
What I'm confused about now is the modem acting strange. Waking up to only the 4 LAN lights on, solid orange. The Power, US/DS & internet light off. Power cycling brings internet back. Hour or two later the issue happens again. Can you or anyone else explain what's happening? It's never done this before and I'm fearing the high readings are causing it or permanently causing it to fail.
I think your mistaken on the Upstream OFDMA. I'm not seeing what your seeing on previous shared screenshots/readings.
My error, you are correct.
Here's an update. Throughout the day the internet would drop and only the LAN lights would be lit up on the modem. I would power cycle to fix the issue. I finally got fed up and found my CM1000v2. Called Cox to have them switch modems. No internet drops at all. So at this point I'm running my old modem & my backup router. So far so good with no issues. Unsure if the high power readings are causing my CM1200 the modem to go into protection mode or something. I also don't know if my other router was an issue either. Anyways here's my readings and logs..
Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords 1 Locked QAM256 5 759000000 Hz 8.5 dBmV 42.7 dB 702499430 0 0 2 Locked QAM256 1 735000000 Hz 8.6 dBmV 42.8 dB 704768324 0 0 3 Locked QAM256 2 741000000 Hz 8.7 dBmV 42.8 dB 704773083 0 0 4 Locked QAM256 3 747000000 Hz 8.4 dBmV 42.7 dB 704777929 0 0 5 Locked QAM256 4 753000000 Hz 8.3 dBmV 42.5 dB 704782990 0 0 6 Locked QAM256 25 117000000 Hz 10.3 dBmV 44.0 dB 700560122 0 0 7 Locked QAM256 6 765000000 Hz 8.1 dBmV 42.5 dB 704790071 0 0 8 Locked QAM256 7 771000000 Hz 8.1 dBmV 42.5 dB 704803309 0 0 9 Locked QAM256 8 777000000 Hz 8.3 dBmV 42.7 dB 704809016 0 0 10 Locked QAM256 26 123000000 Hz 10.3 dBmV 44.2 dB 700602495 0 0 11 Locked QAM256 27 129000000 Hz 10.3 dBmV 44.1 dB 700610136 0 0 12 Locked QAM256 28 135000000 Hz 10.2 dBmV 44.2 dB 700611346 0 0 13 Locked QAM256 29 141000000 Hz 10.0 dBmV 44.3 dB 700619415 0 0 14 Locked QAM256 30 147000000 Hz 10.1 dBmV 44.5 dB 700627159 0 0 15 Locked QAM256 31 153000000 Hz 9.8 dBmV 44.6 dB 700634302 0 0 16 Locked QAM256 32 159000000 Hz 9.9 dBmV 44.4 dB 700641347 0 0 17 Locked QAM256 33 165000000 Hz 10.0 dBmV 44.5 dB 700649540 0 0 18 Locked QAM256 34 171000000 Hz 10.0 dBmV 44.4 dB 700656239 0 0 19 Locked QAM256 35 177000000 Hz 10.2 dBmV 44.5 dB 700664383 0 0 20 Locked QAM256 36 183000000 Hz 10.4 dBmV 44.6 dB 700671436 0 0 21 Locked QAM256 37 189000000 Hz 10.4 dBmV 44.6 dB 700678855 0 0 22 Locked QAM256 38 195000000 Hz 10.5 dBmV 44.6 dB 700686461 0 0 23 Locked QAM256 39 201000000 Hz 10.5 dBmV 44.6 dB 700688038 0 0 24 Locked QAM256 40 207000000 Hz 10.5 dBmV 44.5 dB 700692301 0 0 25 Locked QAM256 41 213000000 Hz 10.7 dBmV 44.5 dB 704862492 0 0 26 Locked QAM256 42 219000000 Hz 10.5 dBmV 44.6 dB 704865790 0 0 27 Locked QAM256 43 225000000 Hz 10.4 dBmV 44.6 dB 704869939 0 0 28 Locked QAM256 44 231000000 Hz 10.4 dBmV 44.7 dB 704874196 0 0 29 Locked QAM256 45 237000000 Hz 10.6 dBmV 44.6 dB 704876853 0 0 30 Locked QAM256 46 243000000 Hz 10.6 dBmV 44.9 dB 704881596 0 0 31 Locked QAM256 47 249000000 Hz 10.6 dBmV 44.7 dB 704875235 0 0 32 Locked QAM256 48 255000000 Hz 10.7 dBmV 44.7 dB 704877546 0 0 Upstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power 1 Locked ATDMA 1 17400000 Hz 37.3 dBmV 2 Locked ATDMA 2 23900000 Hz 37.3 dBmV 3 Locked ATDMA 3 30300000 Hz 37.3 dBmV 4 Locked ATDMA 4 36700000 Hz 36.8 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 Downstream OFDM Channels 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, 3 159 300000000 Hz 11.2 dBmV 43.3 dB 296 ~ 7895 383342351 111509101 0 2 Locked 0, 1, 2, 3 160 918000000 Hz 6.6 dBmV 40.5 dB 2216 ~ 5975 396552908 246947097 0 Upstream OFDMA Channels Channel Lock Status Modulation / Profile ID Channel ID Frequency Power 1 Locked 3, 4, 9, 10, 11, 12, 13 6 36800000 Hz 32.5 dBmV 2 Not Locked 3, 4, 9, 10, 11, 12, 13 0 0 Hz 0.0 dBmV Time Priority Description 2025-06-29, 00:34:48 Notice (6) 2025-06-28, 23:35:41 Critical (3) 2025-06-28, 23:35:10 Notice (6) 2025-06-28, 23:34:52 Critical (3) 2025-06-28, 23:34:50 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:34:00 Warning (5) 2025-06-28, 23:33:56 Notice (6) 2025-06-28, 23:33:55 Notice (6) 2025-06-28, 23:33:50 Notice (6) 2025-06-28, 23:33:49 Warning (5) Power levels are too high. You need to put on a -6Dbm attenuator on the line or your burn up the modems.
Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.
I had another tech here today. He didn't seem to really care at first that all I needed was the attenuator. I told him about the last tech said the power levels good. He pulled up his phone and showed me that they are too high. I let him know the last tech took the attenuator & the high levels without it are causing my CM1200 to go offline(I'm assuming this is why). He went and got the attenuator after explaining the whole situation. Had me look at power levels once it was connected. I also mentioned to him the last tech pretty much just changed a fitting that was showing it's shielding and called it good. He said he should of verified the power levels were too high. I explained I told him that but he said I didn't need the attenuator but didn't leave it behind when he said he would. I'm going to assume the cable at the box on the side of the house is what caused the issue & high power ratings coming in. I'm going to continue to use my CM1000v2 for the moment & switch back to the CM1200 if I have issues with the CM1000v2. Anyways here's my readings...
Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords 1 Locked QAM256 45 237000000 Hz 4.8 dBmV 44.8 dB 242023857 0 0 2 Locked QAM256 1 735000000 Hz 2.3 dBmV 42.5 dB 245459473 0 0 3 Locked QAM256 2 741000000 Hz 2.3 dBmV 42.5 dB 245464259 0 0 4 Locked QAM256 3 747000000 Hz 2.0 dBmV 42.3 dB 245467463 0 0 5 Locked QAM256 4 753000000 Hz 2.0 dBmV 42.2 dB 245473390 0 0 6 Locked QAM256 5 759000000 Hz 2.2 dBmV 42.4 dB 245476741 0 0 7 Locked QAM256 6 765000000 Hz 1.7 dBmV 42.1 dB 245479955 0 0 8 Locked QAM256 7 771000000 Hz 1.8 dBmV 42.1 dB 245482663 0 0 9 Locked QAM256 8 777000000 Hz 1.9 dBmV 42.3 dB 245488004 0 0 10 Locked QAM256 25 117000000 Hz 4.6 dBmV 44.1 dB 241282517 0 0 11 Locked QAM256 26 123000000 Hz 4.6 dBmV 44.2 dB 241290700 0 0 12 Locked QAM256 27 129000000 Hz 4.5 dBmV 44.0 dB 241297698 0 0 13 Locked QAM256 28 135000000 Hz 4.3 dBmV 44.2 dB 241305026 0 0 14 Locked QAM256 29 141000000 Hz 4.1 dBmV 44.3 dB 241312334 0 0 15 Locked QAM256 30 147000000 Hz 4.2 dBmV 44.5 dB 241320452 0 0 16 Locked QAM256 31 153000000 Hz 4.0 dBmV 44.5 dB 241327554 0 0 17 Locked QAM256 32 159000000 Hz 4.1 dBmV 44.4 dB 241335133 0 0 18 Locked QAM256 33 165000000 Hz 4.2 dBmV 44.4 dB 241341971 0 0 19 Locked QAM256 34 171000000 Hz 4.3 dBmV 44.5 dB 241349897 0 0 20 Locked QAM256 35 177000000 Hz 4.6 dBmV 44.6 dB 241356635 0 0 21 Locked QAM256 36 183000000 Hz 4.8 dBmV 44.7 dB 241364913 0 0 22 Locked QAM256 37 189000000 Hz 4.8 dBmV 44.8 dB 241371746 0 0 23 Locked QAM256 38 195000000 Hz 4.9 dBmV 44.6 dB 241379264 0 0 24 Locked QAM256 39 201000000 Hz 4.9 dBmV 44.7 dB 241382403 0 0 25 Locked QAM256 41 213000000 Hz 5.1 dBmV 44.5 dB 245547749 0 0 26 Locked QAM256 42 219000000 Hz 4.8 dBmV 44.6 dB 245551497 0 0 27 Locked QAM256 43 225000000 Hz 4.8 dBmV 44.7 dB 245555328 0 0 28 Locked QAM256 44 231000000 Hz 4.7 dBmV 44.8 dB 245559220 0 0 29 Locked QAM256 40 207000000 Hz 4.9 dBmV 44.5 dB 241418782 0 0 30 Locked QAM256 46 243000000 Hz 4.9 dBmV 44.9 dB 245566569 0 0 31 Locked QAM256 47 249000000 Hz 4.9 dBmV 44.8 dB 245561409 0 0 32 Locked QAM256 48 255000000 Hz 4.9 dBmV 44.6 dB 245563748 0 0 Upstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power 1 Locked ATDMA 1 17400000 Hz 43.3 dBmV 2 Locked ATDMA 2 23900000 Hz 43.8 dBmV 3 Locked ATDMA 3 30300000 Hz 43.8 dBmV 4 Locked ATDMA 4 36700000 Hz 44.3 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 Downstream OFDM Channels 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, 3 159 300000000 Hz 5.1 dBmV 42.5 dB 296 ~ 7895 174342671 49316069 25094 2 Locked 0, 1, 2, 3 160 918000000 Hz 0.1 dBmV 39.8 dB 2216 ~ 5975 170337287 107680602 0 Upstream OFDMA Channels Channel Lock Status Modulation / Profile ID Channel ID Frequency Power 1 Locked 3, 4, 9, 10, 11, 12, 13 6 36800000 Hz 39.0 dBmV 2 Not Locked 3, 4, 9, 10, 11, 12, 13 0 0 Hz 0.0 dBmV Now that looks great. Ya, Power levels were too high. It's good now.
Let us know if you get the CM1200 online and that should looks the same.
