Cable connection issues on Comcast/Xfinity with CBR750

Tutor

Jan 24, 2023

Thank you both for responding. Forgive my ignorance on the subject, but is it the upstream, downstream, or both on which the power is too high?

Also, I did do a FULL factory reset this morning, and other than the login, SSID, and password, I left all other settings at default just to rule things out. This is what the logs show now:

Cable Connection:

Cable Diagnostic

Status: Poor

Action:
[Downstream Power Level]
Try these actions (Click the Refresh button after each step):
1) Make sure the coaxial cable is tightly connected.
2) Remove any unnecessary splitters.
3) Replace any required splitters.
4) Contact your service provider for troubleshooting help.

Internet Access:

Downstream Status:

Upstream Status:

Refresh Save Cable Diagnostic Info

Advanced Information

Frequency Start Value

This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.

Starting Frequency

Startup Procedure

Procedure	Status	Comment
Acquire Downstream Channel	405000000 Hz	Locked
Connectivity State	Ok	Operational
Boot State	Ok	Operational
Security	Enabled	BPI+
IP Provisioning Mode	Honor MDD	honorMdd(4)

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectable
1	Locked	QAM 256	1	405000000 Hz	8.9 dBmV	40.9 dB	0	0
2	Locked	QAM 256	2	411000000 Hz	9.0 dBmV	40.9 dB	0	0
3	Locked	QAM 256	3	417000000 Hz	9.1 dBmV	40.3 dB	3	0
4	Locked	QAM 256	4	423000000 Hz	9.1 dBmV	40.3 dB	0	0
5	Locked	QAM 256	5	429000000 Hz	9.4 dBmV	40.3 dB	0	0
6	Locked	QAM 256	6	435000000 Hz	9.4 dBmV	40.3 dB	10	0
7	Locked	QAM 256	7	441000000 Hz	9.6 dBmV	40.9 dB	0	0
8	Locked	QAM 256	8	453000000 Hz	9.6 dBmV	40.3 dB	0	0
9	Locked	QAM 256	9	459000000 Hz	9.5 dBmV	40.9 dB	0	0
10	Locked	QAM 256	10	465000000 Hz	9.5 dBmV	40.3 dB	3	0
11	Locked	QAM 256	11	471000000 Hz	9.6 dBmV	40.9 dB	0	0
12	Locked	QAM 256	12	477000000 Hz	9.6 dBmV	40.9 dB	0	0
13	Locked	QAM 256	13	483000000 Hz	9.6 dBmV	40.9 dB	0	0
14	Locked	QAM 256	14	489000000 Hz	9.5 dBmV	40.3 dB	0	0
15	Locked	QAM 256	15	495000000 Hz	9.6 dBmV	40.9 dB	0	0
16	Locked	QAM 256	16	501000000 Hz	9.8 dBmV	40.3 dB	0	0
17	Locked	QAM 256	17	507000000 Hz	9.8 dBmV	40.3 dB	0	0
18	Locked	QAM 256	18	513000000 Hz	9.9 dBmV	40.9 dB	0	0
19	Locked	QAM 256	19	519000000 Hz	9.9 dBmV	40.3 dB	0	0
20	Locked	QAM 256	20	525000000 Hz	10.0 dBmV	40.3 dB	0	0
21	Locked	QAM 256	21	531000000 Hz	9.9 dBmV	40.3 dB	0	0
22	Locked	QAM 256	22	537000000 Hz	9.9 dBmV	40.3 dB	0	0
23	Locked	QAM 256	23	543000000 Hz	9.9 dBmV	40.3 dB	0	0
24	Locked	QAM 256	24	549000000 Hz	9.9 dBmV	40.3 dB	0	0
25	Locked	QAM 256	25	555000000 Hz	9.8 dBmV	40.3 dB	0	0
26	Locked	QAM 256	26	561000000 Hz	10.0 dBmV	40.3 dB	0	0
27	Locked	QAM 256	27	567000000 Hz	10.0 dBmV	40.9 dB	0	0
28	Locked	QAM 256	28	573000000 Hz	10.0 dBmV	40.3 dB	0	0
29	Locked	QAM 256	29	579000000 Hz	10.0 dBmV	40.3 dB	0	0
30	Locked	QAM 256	30	585000000 Hz	10.3 dBmV	38.9 dB	0	0
31	Locked	QAM 256	31	591000000 Hz	10.4 dBmV	40.3 dB	0	0
32	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	4	5120 Ksym/sec	16400000 Hz	43.5 dBmV
2	Locked	ATDMA	3	5120 Ksym/sec	22800000 Hz	43.8 dBmV
3	Locked	ATDMA	2	5120 Ksym/sec	29200000 Hz	44.3 dBmV
4	Locked	ATDMA	1	5120 Ksym/sec	35600000 Hz	44.8 dBmV
5	Locked	ATDMA	5	1280 Ksym/sec	39600000 Hz	45.3 dBmV
6	Not Locked	N/A	Unknown	0 Ksym/sec	0 Hz	0.0 dBmV
7	Not Locked	N/A	Unknown	0 Ksym/sec	0 Hz	0.0 dBmV
8	Not Locked	N/A	Unknown	0 Ksym/sec	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	3	45	690000000 Hz	11.0 dBmV	41.7 dB	1108~2987	0	0	0
2	Not Locked	0	0	0 Hz	0.0 dBmV	0.0 dB	0~4095	0	0	0

Upstream OFDMA Channels

Channel	Lock Status	Modulation/Profile ID	Channel ID	Frequency	Power
1	Not Locked	0	0	0 Hz	0.0 dBmV
2	Not Locked	0	0	0 Hz	0.0 dBmV

Current System Time: Tue Jan 24 09:10:51 2023

System Up Time 00:19:31

Event Logs:

Clear Log Refresh

Time	Priority	Description
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Jan 24 2023 08:52:55	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Jan 24 2023 08:52:55	Notice (6)	TLV-11 - unrecognized OID
Jan 24 2023 08:52:55	Critical (3)	Config File Rejected due to Invalid or Unexpected TLV 11
Jan 24 2023 08:53:03	Warning (5)	RCS Partial Service
Jan 24 2023 08:53:04	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW
Jan 24 2023 08:53:12	Alert (2)	CM Certificate Error
Jan 24 2023 08:53:16	Notice (6)	CM-STATUS message sent. Event Type Code: 4

Things seem more stable, but it's only been 15-20 minutes or so. Cable connection still says "Poor" which I guess is due to the power from the line being too high. So I guess I will wait until the Comcast/Xfinity technician comes and ask them how they can address that. Is there anything else I should communicate to them at that time? Any advice would be much appreciated. I'd really hope to have this resolved in one trip, if possible. Thank you for your knowledge on this.

Forum Discussion

Cable connection issues on Comcast/Xfinity with CBR750