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low power level to modem

kcg5036
New Poster

low power level to modem

Hi, I've tried speaking to customer service regarding this a few tmes but have been told everything is within spec.

 

Backstory: over the last month,  I've noticed my internet is signifcantn slower than it used to be.  Begining of May on the speed test I was routninely getting over 230Mbps, now im lucky to get 120.  (on the 200 plan).

 

I checked my modem Status (Arris SB6183 connected to ASUS Blue cave router) and found that my downstream power levels are low and routninely out of spec for DOCSIS 3.0/3.1.

 

1 Locked QAM256 1 405000000 Hz -8.9 dBmV 40.1 dB 0 0
2 Locked QAM256 2 411000000 Hz -9.0 dBmV 40.1 dB 0 0
3 Locked QAM256 3 417000000 Hz -9.5 dBmV 39.8 dB 0 0
4 Locked QAM256 4 423000000 Hz -9.2 dBmV 39.9 dB 0 0
5 Locked QAM256 5 429000000 Hz -9.9 dBmV 39.6 dB 0 0
6 Locked QAM256 6 435000000 Hz -9.9 dBmV 39.6 dB 0 0
7 Locked QAM256 7 441000000 Hz -10.0 dBmV 39.5 dB 0 0
8 Locked QAM256 8 447000000 Hz -10.4 dBmV 39.3 dB 0 0
9 Locked QAM256 9 453000000 Hz -10.0 dBmV 39.3 dB 0 0
10 Locked QAM256 10 459000000 Hz -10.5 dBmV 38.9 dB 0 0
11 Locked QAM256 11 465000000 Hz -10.1 dBmV 38.9 dB 0 0
12 Locked QAM256 12 471000000 Hz -10.3 dBmV 38.9 dB 0 0
13 Locked QAM256 13 477000000 Hz -10.7 dBmV 37.4 dB 0 0
14 Locked QAM256 14 483000000 Hz -10.5 dBmV 37.2 dB 0 0
15 Locked QAM256 15 489000000 Hz -11.1 dBmV 38.6 dB 0 0
16 Locked QAM256 16 495000000 Hz -11.0 dBmV 38.6 dB 0 0
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 5 5120 Ksym/sec 17300000 Hz 53.3 dBmV
2 Locked ATDMA 6 5120 Ksym/sec 23700000 Hz 53.8 dBmV
3 Locked ATDMA 7 5120 Ksym/sec 30100000 Hz 54.0 dBmV
4 Locked ATDMA 8 5120 Ksym/sec 36500000 Hz 54.0 dBmV

These power levels are taken ~15 mins after a reset message was sent.  After about 24 hours i'll see power levels approach -17dBmV on atleast half of the channels.

 

This is the error log since the 28th of May.

Time Not Established Critical (3) No Ranging Response received - T3 time-out
Thu May 28 17:15:38 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) No Ranging Response received - T3 time-out
Wed Jun 03 03:15:39 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) No Ranging Response received - T3 time-out
Time Not Established Critical (3) No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=74:ea:e8:ee:15:ef;CMTS-MAC=00:01:5c:ac:4a:6b;CM-QOS=1.0;CM-VER=3.0;
Time Not Established Critical (3) No Ranging Response received - T3 time-out
Fri Jun 05 18:26:04 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=74:ea:e8:ee:15:ef;CMTS-MAC=00:01:5c:ac:4a:6b;CM-QOS=1.1;CM-VER=3.0;
Sun Jun 07 15:11:46 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) No Ranging Response received - T3 time-out
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6

 

I appreciate any help in troubleshooting!  Customer service hasn't been much help since I own the modem and router.

EG
Expert

Re: low power level to modem

Both the downstream power levels and the upstream power levels are out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

In a self troubleshooting 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 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

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.



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