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jfalko117
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Saturday, June 25th, 2022 3:45 AM

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Large number of Uncorrected errors on every downstream channel - MB8600

Hello, I have a new Motorola MB8600 modem. There are a large amount of uncorrected errors on every downstream channel, and I'm stuck wondering why. I understand that errors aren't too big of an issue, but uncorrected errors are and typically are a symptom of equipment failure somewhere within the system.

Most posts I've read have either been only a few channels having any errors, or they have some signal or power levels out of spec. I'm no expert, but from what I can tell - my power levels are all reasonable and signal strength seems to be good.

This was happening on my previous modem (SB8200) with the same connection issues and roughly identical uncorrected error counts over the same time period.

I have been facing this issue for quite a bit longer than I'd prefer, and have frequent packet loss, an unstable connection, as well as intermittent home internet outages.

I have tried replacing a few pieces of equipment on my end to remedy it without any success. I have replaced the coaxial cable from the wall to my modem, ethernet cables, as well as just purchased a new modem.

The connection channel information below is from the MB8600.

I am wondering if it could be xfinity's equipment, as I have no splitters or any odd connections between the modem and the line from the street.

Any and all help is appreciated greatly!

System Up Time 0 days 00h:19m:43s

Downstream Bonded Channels
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 29 651.0 1.0 41.1 7011 9402
   2 Locked QAM256 2 489.0 3.8 42.6 11499 10256
   3 Locked QAM256 3 495.0 3.1 32.3 14415 17329
   4 Locked QAM256 4 501.0 2.1 39.1 35695 19079
   5 Locked QAM256 5 507.0 2.1 42.1 9891 10965
   6 Locked QAM256 6 513.0 1.7 41.9 15091 20396
   7 Locked QAM256 7 519.0 0.8 41.4 36514 19390
   8 Locked QAM256 8 525.0 0.5 41.5 10811 10150
   9 Locked QAM256 9 531.0 0.9 41.5 11277 18666
   10 Locked QAM256 10 537.0 -0.1 40.8 24473 16966
   11 Locked QAM256 11 543.0 0.2 41.2 9126 8078
   12 Locked QAM256 12 549.0 1.1 41.8 8132 13520
   13 Locked QAM256 13 555.0 1.2 41.5 8159 10768
   14 Locked QAM256 14 561.0 1.5 41.9 7787 6763
   15 Locked QAM256 15 567.0 2.0 42.1 7736 6776
   16 Locked QAM256 16 573.0 1.9 42.0 7587 5695
   17 Locked QAM256 17 579.0 1.9 41.9 7379 8100
   18 Locked QAM256 18 585.0 1.8 42.0 8082 7408
   19 Locked QAM256 19 591.0 1.7 41.5 7642 5476
   20 Locked QAM256 20 597.0 2.2 41.9 6831 9049
   21 Locked QAM256 21 603.0 2.1 41.9 7352 8318
   22 Locked QAM256 22 609.0 2.1 42.1 7288 5027
   23 Locked QAM256 23 615.0 2.5 42.4 6365 7284
   24 Locked QAM256 24 621.0 2.4 40.8 7340 6852
   25 Locked QAM256 25 627.0 2.3 36.1 6311 7487
   26 Locked QAM256 26 633.0 2.1 38.9 6932 7012
   27 Locked QAM256 27 639.0 1.7 35.6 7102 4709
   28 Locked QAM256 28 645.0 1.6 41.7 6386 10238
   29 Locked QAM256 30 657.0 0.7 41.0 6899 5187
   30 Locked QAM256 31 663.0 0.6 40.9 6201 11176
   31 Locked QAM256 32 669.0 0.9 41.0 6681 10025
   32 Locked OFDM PLC 37 690.0 1.7 36.3 24932792 1962704

Upstream Bonded Channels
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 1 2560 10.4 55.3
   2 Locked SC-QAM 2 5120 16.4 58.3
   3 Locked SC-QAM 3 5120 22.8 53.0
   4 Locked SC-QAM 4 5120 29.2 52.8
   5 Locked SC-QAM 5 5120 35.6 52.0
   6 Locked SC-QAM 6 1280 39.6 51.5

Question

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Updated 

3 years ago

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jfalko117

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3 Messages

3 years ago

Ok so I refreshed the connection status page to verify these signal levels this morning - they were still at the same magnitude as last night. I then noticed the upstream power levels being quite high, so I unplugged my modem and let it sit for about 5 minutes.

After plugging it back in, none of the the upstream power levels go beyond 50.0. I will give it until this evening to make sure that the uncorrected errors aren't piling up again, but so far this seems to be good.

0

0

EG

Expert

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110.3K Messages

3 years ago

50 is marginal. 51 is too high / out of spec. They will go higher again. Especially in the peak heating of a Summer day.

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, etc. Splitters should be swapped with known to be good / new ones to test.

Also check the coax cable for any damage such as cuts, nicks, kinks, sharp bends, etc.

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.


Good luck with it !

(edited)

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jfalko117

Visitor

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3 Messages

@EG​ Thanks EG! It looks like the signal levels have corrected and are all within spec. There were no splitters on the line, but I installed a new coaxial cable from the modem to the coupling attached to the drop. Everything seems to be tightened up as well as possible - about a half turn past hand tightened. I am still getting uncorrected errors on all channels, though.

How should I go about getting a technician out to my home, specifically one who understands all of this fully?

  System Up Time 0 days 07h:09m:21s  
  


   Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 42 399.0 8.0 44.0 62760 77899
   2 Locked QAM256 1 483.0 5.2 42.9 41532 37504
   3 Locked QAM256 2 489.0 4.8 42.7 38947 30850
   4 Locked QAM256 3 495.0 4.1 42.3 47877 50456
   5 Locked QAM256 4 501.0 3.6 42.1 45540 38915
   6 Locked QAM256 5 507.0 3.3 42.2 36352 27244
   7 Locked QAM256 6 513.0 2.4 41.6 37308 30682
   8 Locked QAM256 7 519.0 1.9 41.3 41587 36279
   9 Locked QAM256 8 525.0 1.6 41.3 37350 29401
   10 Locked QAM256 9 531.0 1.3 41.2 43721 39453
   11 Locked QAM256 10 537.0 0.7 40.7 50214 53811
   12 Locked QAM256 11 543.0 1.1 40.9 37047 19785
   13 Locked QAM256 12 549.0 1.5 41.2 40026 26976
   14 Locked QAM256 13 555.0 2.0 41.4 38758 24730
   15 Locked QAM256 14 561.0 2.3 41.5 32376 19833
   16 Locked QAM256 15 567.0 2.7 41.8 35149 22980
   17 Locked QAM256 16 573.0 2.6 41.8 32182 17573
   18 Locked QAM256 17 579.0 2.5 41.6 38084 26652
   19 Locked QAM256 18 585.0 2.6 41.7 35560 23277
   20 Locked QAM256 19 591.0 2.4 41.6 32431 19405
   21 Locked QAM256 33 459.0 6.0 43.1 40548 31627
   22 Locked QAM256 34 465.0 5.7 43.0 47498 50283
   23 Locked QAM256 35 471.0 5.5 43.0 41700 30537
   24 Locked QAM256 36 477.0 5.7 43.1 41941 32874
   25 Locked OFDM PLC 37 690.0 2.2 39.9 367059685 588328
   26 Locked QAM256 38 429.0 5.3 42.9 60467 79161
   27 Locked QAM256 39 435.0 5.7 43.0 64987 70350
   28 Locked QAM256 40 441.0 5.3 42.9 47016 40627
   29 Locked QAM256 41 453.0 5.4 42.8 50536 53939
   30 Locked QAM256 43 405.0 7.3 43.7 47936 64640
   31 Locked QAM256 44 411.0 7.0 43.4 41498 65991
   32 Locked QAM256 45 417.0 6.4 43.2 51361 65492


   Upstream Bonded Channels  
  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 1 2560 10.4 44.8
   2 Locked SC-QAM 2 5120 16.4 46.8
   3 Locked SC-QAM 3 5120 22.8 47.3
   4 Locked SC-QAM 4 5120 29.2 48.8
   5 Locked SC-QAM 5 5120 35.6 49.0
   6 Locked SC-QAM 6 1280 39.6 48.0

3 years ago

0

CCElizabeth

Problem Solver

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908 Messages

Hello @jfalko117. I would be happy to continue troubleshooting with you. You are in the right place for help. My team will stay with you until this is resolved. 

 

Please send a private message with your first and last name, as well as complete service address to "Xfinity Support". To do so, click on the chat icon located at the top right of this forums page.

 

  1. Click "Sign In" if necessary
  2. Click the "Direct Messaging" icon (upper right corner of this page)
  3. Click the "New message" (pencil and paper) icon
  4. Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list
  5. Type your message in the text area near the bottom of the window
  6. Press Enter to send your message

 

I no longer work for Comcast.

3 years ago

0

EG

Expert

 • 

110.3K Messages

3 years ago

@jfalko117 @XfinityElizabethA 

Please circle back here and post any possible solutions for the issue here in the open forums so that all readers here may benefit from the exchange / info. This is in keeping with the spirit for which these public help forums were originally intended. Thank you.

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