Visitor

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4 Messages

Tuesday, November 29th, 2022

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Downstream light blinking

I have been having issues the past couple of days with my modems downstream light blinking and random laggy connections. Ive replaced coax cabled in my apartment. atleast the ones  that i could to ensure it wasnt any of those. I noticed that 2 of my downstream channels arent locked. Here is a table to my modems downstream channels. 

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 29 651000000 Hz -10.7 dBmV 37.2 dB 0 0
2 Locked QAM256 17 579000000 Hz -11.7 dBmV 32.3 dB 0 0
3 Locked QAM256 18 585000000 Hz -11.4 dBmV 34.0 dB 0 0
4 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
5 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
6 Locked QAM256 21 603000000 Hz -11.6 dBmV 32.6 dB 0 0
7 Locked QAM256 22 609000000 Hz -11.9 dBmV 37.0 dB 0 0
8 Locked QAM256 23 615000000 Hz -12.1 dBmV 36.9 dB 0 0
9 Locked QAM256 24 621000000 Hz -11.8 dBmV 36.3 dB 0 0
10 Locked QAM256 25 627000000 Hz -11.6 dBmV 34.6 dB 6125 0
11 Locked QAM256 26 633000000 Hz -10.8 dBmV 36.3 dB 12197 7
12 Locked QAM256 27 639000000 Hz -11.2 dBmV 36.1 dB 55891 14494
13 Locked QAM256 28 645000000 Hz -11.0 dBmV 30.7 dB 1137968 1564435
14 Locked QAM256 30 657000000 Hz -11.0 dBmV 37.1 dB 0 0
15 Locked QAM256 32 663000000 Hz -11.6 dBmV 36.9 dB 0 0
16 Locked QAM256 33 669000000 Hz -12.1 dBmV 36.6 dB 0 0
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Visitor

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4 Messages

3 years ago

Also note that this is also after restarting my modem.

Expert

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111.9K Messages

3 years ago

The downstream power is weak / too low as are some of the SNR values.  That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

I'm going to provide some tips that may or may not apply. YMMV.

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, abrasions, 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)

Expert

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111.9K Messages

3 years ago

You didn't post the upstream, but the downstream is a bit better but it's still on the weak side. You should book a tech visit as the power appears to be too weak coming from the pole to begin with. Excess attenuation needs to be removed or an amp needs to be adjusted.

Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. And if the problem is found to be on their side of the demarcation point, there will not be any charge.


Good luck !

Visitor

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4 Messages

@EG​ Here are the upstreams.

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 5 5120 Ksym/sec 35600000 Hz 46.8 dBmV
2 Locked ATDMA 6 5120 Ksym/sec 29200000 Hz 46.5 dBmV
3 Locked ATDMA 7 5120 Ksym/sec 22800000 Hz 46.3 dBmV
4 Locked ATDMA 8 5120 Ksym/sec 16400000 Hz

46.5 dBmV

I went ahead and booked a tech to come out. Hopefully its an easy fix. Thank you for the guidance. 

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