internet keeps dropping. sb8200 modem all lights turn off except for the top one

[acf1]

Hi

My internet keeps dropping. sb8200 modem all lights turn off except for the top one. I have to unplug it, wait 10 seconds and replug it in order for the other lights to come back. What is the issue?

current status and logs below:

Procedure	Status	Comment
Acquire Downstream Channel	495000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Configuration File	OK
Security	Enabled	BPI+
DOCSIS Network Access Enabled	Allowed

Channel ID	Lock Status	Modulation	Frequency	Power	SNR/MER	Corrected	Uncorrectables
20	Locked	QAM256	495000000 Hz	-1.3 dBmV	40.7 dB	0	0
12	Locked	QAM256	447000000 Hz	-0.4 dBmV	40.9 dB	0	0
13	Locked	QAM256	453000000 Hz	-0.5 dBmV	40.9 dB	0	0
14	Locked	QAM256	459000000 Hz	-0.5 dBmV	40.8 dB	0	0
15	Locked	QAM256	465000000 Hz	-0.7 dBmV	40.8 dB	0	0
16	Locked	QAM256	471000000 Hz	-0.9 dBmV	40.8 dB	0	0
17	Locked	QAM256	477000000 Hz	-0.9 dBmV	40.7 dB	0	0
18	Locked	QAM256	483000000 Hz	-1.2 dBmV	40.6 dB	0	0
19	Locked	QAM256	489000000 Hz	-1.2 dBmV	40.8 dB	0	0
21	Locked	QAM256	507000000 Hz	-1.0 dBmV	40.0 dB	0	0
22	Locked	QAM256	513000000 Hz	-0.8 dBmV	40.8 dB	0	0
23	Locked	QAM256	519000000 Hz	-0.6 dBmV	40.9 dB	0	0
24	Locked	QAM256	525000000 Hz	-0.7 dBmV	40.7 dB	0	0
25	Locked	QAM256	531000000 Hz	-0.7 dBmV	40.7 dB	0	0
26	Locked	QAM256	537000000 Hz	-0.8 dBmV	40.7 dB	0	0
27	Locked	QAM256	543000000 Hz	-0.8 dBmV	40.7 dB	0	0
28	Locked	QAM256	549000000 Hz	-1.1 dBmV	40.6 dB	0	0
29	Locked	QAM256	555000000 Hz	-0.9 dBmV	40.6 dB	0	0
30	Locked	QAM256	561000000 Hz	-1.0 dBmV	40.6 dB	0	0
31	Locked	QAM256	567000000 Hz	-1.2 dBmV	40.4 dB	0	0
32	Locked	QAM256	573000000 Hz	-0.8 dBmV	40.6 dB	0	0
33	Locked	QAM256	579000000 Hz	-0.7 dBmV	40.6 dB	0	0
34	Locked	QAM256	585000000 Hz	-0.5 dBmV	40.7 dB	0	0
35	Locked	QAM256	591000000 Hz	-0.6 dBmV	40.6 dB	0	0
36	Locked	QAM256	597000000 Hz	-0.7 dBmV	40.5 dB	0	0
37	Locked	QAM256	603000000 Hz	-0.9 dBmV	40.2 dB	0	0
38	Locked	QAM256	609000000 Hz	-0.8 dBmV	40.5 dB	0	0
39	Locked	QAM256	615000000 Hz	-0.9 dBmV	40.5 dB	0	0
40	Locked	QAM256	621000000 Hz	-0.7 dBmV	40.4 dB	0	0
41	Locked	QAM256	627000000 Hz	-0.8 dBmV	40.4 dB	0	0
42	Locked	QAM256	633000000 Hz	-1.1 dBmV	40.3 dB	0	0
48	Locked	Other	688000000 Hz	-0.6 dBmV	38.8 dB	181267398	0

Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	1	Locked	SC-QAM Upstream	17300000 Hz	6400000 Hz	44.0 dBmV
2	4	Locked	SC-QAM Upstream	36700000 Hz	6400000 Hz	43.0 dBmV
3	3	Locked	SC-QAM Upstream	30300000 Hz	6400000 Hz	43.0 dBmV
4	2	Locked	SC-QAM Upstream	23700000 Hz	6400000 Hz	43.0 dBmV
5	5	Locked	SC-QAM Upstream	41200000 Hz	1600000 Hz	44.0 dBmV

05/26/2020 00:59	67061600	6	"DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	2436694066	6	"Honoring MDD; IP provisioning mode = IPv6"
01/01/1970 00:00	84000100	3	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	84000100	3	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	84000100	3	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
05/25/2020 08:44	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
05/25/2020 08:44	84000500	3	"SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	84000100	3	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	84000100	3	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
05/25/2020 06:44	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
05/25/2020 06:44	84000500	3	"SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"
01/01/1970 00:00	84000100	3	"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
05/16/2020 06:36	82000500	3	"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=14:c0:3e:01:cc:f1;CMTS-MAC=00:01:5c:65:14:7f;CM-QOS=1.1;CM-VER=3.1;"

[EG · Accepted solution]

Even though the signal stats looked o/k at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is intermittent noise ingressing into the line(s) somewhere.

There are other signal stat figures that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.

I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They can check the CMTS (Cable Modem Termination System) for any real time degradation and / or error reports, see your node / cable plant and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.

You should get a reply here in your topic. Good luck !

[ComcastAmira]

Hello @acf1, thanks for reaching out to our Digital Care Team through our Forums page. I'm sorry to hear about the connection issues you have been experiencing. I can definitely see how inconvenient and frustrating that must be especially during these troubling times. I would love to assist you and further look into this on my end. Can you please send me a private message including your first and last name as it appears on the account? 

To send me a Private Message, please click my name “ComcastAmira” and click “send a message".