Re: CM1100 - 3 Day Old, keeps disconnection with high upstream power, using Spectrum

lordhung · ‎2020-07-10

Just got my modem 3 days ago and set it up. Had a Spectrum tech come out yesterday and took out extra splitters and checked all my signals. I don't think it made much a difference. My upstream power hovers around 51-52 dB so any flucutations to that spikes it over 53 dB and causes a T3 error and disconnect.

Almost every Spectrum rep wants to blame my for using my own equipment, even though I had this problem with my old modem and bought this modem to upgrade. I just had it re-provisioned this morning after a factory reset of the modem and the issue is still happening.

My coax is running straight from a grounding box to my outlet, then to a splitter that goes to my HD-DVR box and my modem. There was am amp there before that the tech took out yesterday; he said it was bad. However, before the tech visit and after, I did not see a noticable change in upstream power.

Is there anything I can do? Would exchanging the modem for another CM1100 have any difference? I'm not sure it would, as when there is connection, the model works great, but the disconnects happen sometimes every minute.

FURRYe38 · ‎2020-07-10

The user of High Power signals on the line are probably one issue.
The CM1100 is a solid modem if the signals are set right. The ISP should know this.

lordhung · ‎2020-07-10

Modem Status:

Apply Cancel

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

Procedure	Status	Comment
Acquire Downstream Channel	777000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv4 only

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	28	777000000 Hz	-3.4 dBmV	42.0 dB	115624863	1960	2806
2	Locked	QAM256	1	615000000 Hz	0.2 dBmV	43.6 dB	114482630	4759	6042
3	Locked	QAM256	2	621000000 Hz	0.5 dBmV	43.4 dB	114480288	4755	5886
4	Locked	QAM256	3	627000000 Hz	0.4 dBmV	43.8 dB	114484903	4369	5681
5	Locked	QAM256	4	633000000 Hz	-0.2 dBmV	43.5 dB	114488865	4134	5424
6	Locked	QAM256	5	639000000 Hz	0.0 dBmV	43.7 dB	114492659	4021	5240
7	Locked	QAM256	6	645000000 Hz	0.0 dBmV	43.5 dB	114495919	3917	5175
8	Locked	QAM256	7	651000000 Hz	-0.2 dBmV	43.4 dB	114499612	3851	5067
9	Locked	QAM256	8	657000000 Hz	-0.6 dBmV	43.4 dB	114502924	3654	4684
10	Locked	QAM256	9	663000000 Hz	-0.8 dBmV	43.3 dB	114507932	3505	4461
11	Locked	QAM256	10	669000000 Hz	-0.9 dBmV	43.1 dB	114512110	3517	4279
12	Locked	QAM256	11	675000000 Hz	-1.5 dBmV	42.6 dB	114515786	3304	4310
13	Locked	QAM256	12	681000000 Hz	-2.1 dBmV	42.6 dB	114519677	3317	4263
14	Locked	QAM256	13	687000000 Hz	-1.7 dBmV	42.6 dB	114523325	3129	4266
15	Locked	QAM256	14	693000000 Hz	-1.5 dBmV	42.6 dB	114526607	3181	4094
16	Locked	QAM256	15	699000000 Hz	-1.7 dBmV	42.5 dB	114531887	3157	3861
17	Locked	QAM256	16	705000000 Hz	-1.9 dBmV	42.2 dB	114535435	3072	4596
18	Locked	QAM256	17	711000000 Hz	-1.4 dBmV	42.3 dB	114540112	2802	3708
19	Locked	QAM256	18	717000000 Hz	-0.9 dBmV	42.7 dB	114544324	2655	3504
20	Locked	QAM256	19	723000000 Hz	-1.5 dBmV	42.6 dB	114548196	2497	3442
21	Locked	QAM256	20	729000000 Hz	-1.6 dBmV	42.5 dB	114552057	2464	3434
22	Locked	QAM256	21	735000000 Hz	-1.4 dBmV	42.9 dB	114556020	2345	3271
23	Locked	QAM256	22	741000000 Hz	-1.3 dBmV	43.0 dB	114560207	2126	3014
24	Locked	QAM256	23	747000000 Hz	-1.9 dBmV	42.8 dB	114563759	2396	2999
25	Locked	QAM256	24	753000000 Hz	-2.2 dBmV	42.6 dB	114567680	2027	3026
26	Locked	QAM256	25	759000000 Hz	-1.9 dBmV	42.8 dB	114571795	2131	2969
27	Locked	QAM256	26	765000000 Hz	-2.2 dBmV	42.8 dB	114575593	2062	2805
28	Locked	QAM256	27	771000000 Hz	-2.7 dBmV	42.4 dB	114579916	2006	2881
29	Locked	QAM256	29	783000000 Hz	-2.6 dBmV	42.6 dB	114603602	1911	2843
30	Locked	QAM256	30	789000000 Hz	-2.3 dBmV	42.7 dB	114587995	1719	2595
31	Locked	QAM256	31	795000000 Hz	-2.8 dBmV	42.3 dB	114591335	1689	2554
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

<Upstream Bonded Channels (Partial Service)<

Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	1	17600000 Hz	51.3 dBmV
2	Locked	ATDMA	2	24000000 Hz	52.8 dBmV
3	Locked	ATDMA	3	30400000 Hz	58.8 dBmV
4	Locked	ATDMA	4	36800000 Hz	53.3 dBmV
5	Not Locked	Unknown	0	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	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	0, 1, 2, 255	159	848000000 Hz	-3.0 dBmV	39.8 dB	1108 ~ 2987	301281835	210154739	25
2	Not Locked	0, 255	0	0 Hz	1.9 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	Unknown	0	0 Hz	0 dBmV
2	Not Locked	Unknown	0	0 Hz	0 dBmV

plemans · ‎2020-07-10

The 58dbmv would cause issues on the line.

Spectrum would need to recheck the line. They fight checking lines.

I've actually had to rent one of their modems to prove to them it wasn't the "third party" device and get them to fix a line. Then once its fixed, going back to my own modem.

lordhung · ‎2020-07-10

So a tech came today and checked everything from the pole drop to the modem line. Replaced pole connectors, the tech who came yesreday forgot to crimp a fitting smdh.

However, there is an issue with the modem too.

I still have my old modem so I hooked and rehooked it up to compare the 12 year old SBG6580 and the 3 day old CM1100.

Why is there an extra 2-3 dBmV on the CM1100? Is this normal or do I have a bad modem?

SBG6580:

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Corrected	Uncorrectables
1	Locked	QAM256	1	615000000 Hz	3.3 dBmV	42.0 dB	0	0
2	Locked	QAM256	2	621000000 Hz	3.3 dBmV	42.5 dB	0	0
3	Locked	QAM256	3	627000000 Hz	3.4 dBmV	42.0 dB	0	0
4	Locked	QAM256	4	633000000 Hz	2.9 dBmV	41.9 dB	0	0
5	Locked	QAM256	5	639000000 Hz	2.5 dBmV	41.9 dB	0	0
6	Locked	QAM256	6	645000000 Hz	2.9 dBmV	42.0 dB	0	0
7	Locked	QAM256	7	651000000 Hz	2.6 dBmV	42.0 dB	0	0
8	Locked	QAM256	8	657000000 Hz	2.2 dBmV	41.4 dB	0	0

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	2	5120 Ksym/sec	24000000 Hz	47.0 dBmV
2	Locked	ATDMA	1	5120 Ksym/sec	17600000 Hz	46.2 dBmV
3	Locked	ATDMA	3	5120 Ksym/sec	30400000 Hz	47.7 dBmV
4	Locked	ATDMA	4	5120 Ksym/sec	36800000 Hz	48.2 dBmV

CM1100:

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	759000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv4 only

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	25	759000000 Hz	0.0 dBmV	40.5 dB	62683378	0	0
2	Locked	QAM256	1	615000000 Hz	2.1 dBmV	43.3 dB	61724613	0	0
3	Locked	QAM256	2	621000000 Hz	2.2 dBmV	43.3 dB	61727864	0	0
4	Locked	QAM256	3	627000000 Hz	2.0 dBmV	43.2 dB	61731617	0	0
5	Locked	QAM256	4	633000000 Hz	1.5 dBmV	42.9 dB	61734745	0	0
6	Locked	QAM256	5	639000000 Hz	1.6 dBmV	43.1 dB	61736552	0	0
7	Locked	QAM256	6	645000000 Hz	1.4 dBmV	43.0 dB	61741901	0	0
8	Locked	QAM256	7	651000000 Hz	1.2 dBmV	42.7 dB	61746046	0	0
9	Locked	QAM256	8	657000000 Hz	1.1 dBmV	42.7 dB	61749297	0	0
10	Locked	QAM256	9	663000000 Hz	0.9 dBmV	42.4 dB	61752859	0	0
11	Locked	QAM256	10	669000000 Hz	0.9 dBmV	42.4 dB	61756324	0	0
12	Locked	QAM256	11	675000000 Hz	0.5 dBmV	41.6 dB	61761621	0	0
13	Locked	QAM256	12	681000000 Hz	0.3 dBmV	42.0 dB	61764778	0	0
14	Locked	QAM256	13	687000000 Hz	0.6 dBmV	41.6 dB	61768533	0	0
15	Locked	QAM256	14	693000000 Hz	0.6 dBmV	41.0 dB	61773030	0	0
16	Locked	QAM256	15	699000000 Hz	0.3 dBmV	40.6 dB	61776696	0	0
17	Locked	QAM256	16	705000000 Hz	0.0 dBmV	40.1 dB	61778387	211	867
18	Locked	QAM256	17	711000000 Hz	0.4 dBmV	39.8 dB	61783098	118	494
19	Locked	QAM256	18	717000000 Hz	0.7 dBmV	40.0 dB	61787685	0	0
20	Locked	QAM256	19	723000000 Hz	0.1 dBmV	40.3 dB	61791148	0	0
21	Locked	QAM256	20	729000000 Hz	-0.1 dBmV	41.3 dB	61794421	0	0
22	Locked	QAM256	21	735000000 Hz	0.1 dBmV	42.2 dB	61798302	0	0
23	Locked	QAM256	22	741000000 Hz	0.3 dBmV	41.6 dB	61802556	0	0
24	Locked	QAM256	23	747000000 Hz	-0.2 dBmV	40.7 dB	61805961	0	0
25	Locked	QAM256	24	753000000 Hz	-0.3 dBmV	40.4 dB	61810009	1	0
26	Locked	QAM256	26	765000000 Hz	-0.1 dBmV	40.6 dB	61813549	0	0
27	Locked	QAM256	27	771000000 Hz	-0.6 dBmV	40.4 dB	61817160	0	0
28	Locked	QAM256	28	777000000 Hz	-1.3 dBmV	40.4 dB	61810387	3794	6724
29	Locked	QAM256	29	783000000 Hz	-0.5 dBmV	40.9 dB	61820554	2265	1617
30	Locked	QAM256	30	789000000 Hz	-0.2 dBmV	40.9 dB	61825204	0	0
31	Locked	QAM256	31	795000000 Hz	-0.9 dBmV	40.6 dB	61827802	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

Upstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	1	17600000 Hz	49.5 dBmV
2	Locked	ATDMA	2	24000000 Hz	50.5 dBmV
3	Locked	ATDMA	3	30400000 Hz	50.5 dBmV
4	Locked	ATDMA	4	36800000 Hz	51.0 dBmV
5	Not Locked	Unknown	0	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	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	0, 1, 2, 255	159	848000000 Hz	-1.0 dBmV	39.5 dB	1108 ~ 2987	161967520	111423613	0
2	Not Locked	0, 255	0	0 Hz	5.5 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	Unknown	0	0 Hz	0 dBmV
2	Not Locked	Unknown	0	0 Hz	0 dBmV

plemans · ‎2020-07-10

Your signal power levels are entirely within spec now. It could be because you're going from 2 different manufacturers. or going from a 8x4 modem to a 32x8 modem with docsis 3.1.

tough to say exactly.

FURRYe38 · ‎2020-07-11

Take the CM modem back and get it replaced. Possible faulty modem you have.