Netgear cm 1200 Intermittent connection

I am having problems with my internet connection getting dropped a lot somehow. I'm not very educated on how all of this works and know only the very basics. On all of my connected devices, a...

mattoram
Jul 27, 2021
Well Netgear sent out a new modem and everything has been working perfectly for about a week, so far. The event log has been completely clear with no errors.

FURRYe38

Guru - Experienced User

Jul 14, 2021

Please post a copy and paste of the modems connection status page.
Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box.
Be sure your using good quality RG6 coax cable up to the modem.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853
https://highspeed.tips/docsis-events/

What is the brand and model of the host wifi router connected to the modem?

mattoram

Tutor

Jul 14, 2021

Here is the connection Status. I have checked all of the connections, cables, and no splitters. All of that was checked previously too when I installed this Netgear cm1200 modem and Netgear X6S R8000p AC4000 router. I went through all of the ISP provisions this morning and reset the router and Modem. It worked well for a few minutes, then back to the same crap. I have xfinity coming out tomorrow morning to see if anything is wrong with the signal getting to me. I really don't think that's it. It worked perfectly for 6 months and nothing has changed. I was just reading some reviews of the cm1200 and it appears I'm not the only one having these problems. I need this to work correctly because I work from home. If I need a new router, I don't want to wait for netgear to decide to send me another in a month. Should I just go back to the xfinity modem and connect it to my router, or is there another brand modem I should buy. I'm not terribly concerned about the cost, I just need it to work.

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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	663000000 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	Uncorrectables
1	Locked	QAM256	40	663000000 Hz	-4.3 dBmV	38.4 dB	0	0
2	Locked	QAM256	17	525000000 Hz	-5.9 dBmV	38.5 dB	0	0
3	Locked	QAM256	18	531000000 Hz	-5.1 dBmV	38.7 dB	0	0
4	Locked	QAM256	19	537000000 Hz	-5.2 dBmV	38.7 dB	0	0
5	Locked	QAM256	20	543000000 Hz	-4.8 dBmV	38.8 dB	0	0
6	Locked	QAM256	21	549000000 Hz	-5.1 dBmV	38.8 dB	0	0
7	Locked	QAM256	22	555000000 Hz	-4.9 dBmV	38.8 dB	0	0
8	Locked	QAM256	23	561000000 Hz	-5.1 dBmV	38.3 dB	0	0
9	Locked	QAM256	24	567000000 Hz	-4.8 dBmV	38.6 dB	0	0
10	Locked	QAM256	25	573000000 Hz	-4.6 dBmV	38.8 dB	0	0
11	Locked	QAM256	26	579000000 Hz	-4.2 dBmV	38.8 dB	0	0
12	Locked	QAM256	27	585000000 Hz	-4.1 dBmV	38.8 dB	0	0
13	Locked	QAM256	28	591000000 Hz	-3.8 dBmV	38.9 dB	0	0
14	Locked	QAM256	29	597000000 Hz	-3.7 dBmV	38.8 dB	0	0
15	Locked	QAM256	30	603000000 Hz	-3.5 dBmV	38.8 dB	0	0
16	Locked	QAM256	31	609000000 Hz	-3.6 dBmV	38.9 dB	0	0
17	Locked	QAM256	32	615000000 Hz	-3.7 dBmV	38.9 dB	0	0
18	Locked	QAM256	33	621000000 Hz	-3.6 dBmV	38.9 dB	0	0
19	Locked	QAM256	34	627000000 Hz	-4 dBmV	38.8 dB	0	0
20	Locked	QAM256	35	633000000 Hz	-3.9 dBmV	38.7 dB	0	0
21	Locked	QAM256	36	639000000 Hz	-4.4 dBmV	38.5 dB	0	0
22	Locked	QAM256	37	645000000 Hz	-4 dBmV	38.5 dB	0	0
23	Locked	QAM256	38	651000000 Hz	-4.5 dBmV	38.4 dB	0	0
24	Locked	QAM256	39	657000000 Hz	-4.1 dBmV	38.5 dB	0	0
25	Locked	QAM256	41	669000000 Hz	-3.7 dBmV	38.5 dB	0	0
26	Locked	QAM256	42	675000000 Hz	-3.7 dBmV	38.2 dB	0	0
27	Locked	QAM256	43	681000000 Hz	-3.1 dBmV	38.4 dB	0	0
28	Locked	QAM256	44	687000000 Hz	-3 dBmV	38.5 dB	0	0
29	Locked	QAM256	45	693000000 Hz	-2.8 dBmV	38.4 dB	0	0
30	Locked	QAM256	46	699000000 Hz	-3.3 dBmV	38.2 dB	0	0
31	Locked	QAM256	47	705000000 Hz	-3.4 dBmV	38.2 dB	0	0
32	Not Locked	Unknown	0	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	1	5120 Ksym/sec	16400000 Hz	50.3 dBmV
2	Locked	ATDMA	2	5120 Ksym/sec	22800000 Hz	50.3 dBmV
3	Locked	ATDMA	3	5120 Ksym/sec	29200000 Hz	50.3 dBmV
4	Locked	ATDMA	4	5120 Ksym/sec	35600000 Hz	48.8 dBmV
5	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	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	0 ,1 ,2 ,3	48	805000000 Hz	-6.2 dBmV	36.4 dB	1168 ~ 2927	192237126	188532778	0
2	Not Locked	0	0	0 Hz	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 dBmV
2	Not Locked	0	0	0 Hz	0 dBmV

Extended Upstream Transmit Power

Enable Extended Upstream Transmit Power

Current System Time:Wed Jul 14 15:53:39 2021

System Up Time:05:25:51

mattoram
Tutor
Jul 15, 2021
Xfinity just tested all of the lines and signals, and everything is working on their end. It looks like the modem may be the issue. Now I need to figure out if it needs to be replaced, repaired.
- FURRYe38
  Guru - Experienced User
  Jul 15, 2021
  Might try a different modem for short term to see if problem follows or not. Rent the ISP modem or find another CM1200...or similar...
  Contact NG support for additional help and information. See what your options are for a RMA.
  - mattoram
    Tutor
    Jul 17, 2021
    Netgear is sending out another modem but I'm not convinced that's the problem. The technician I was working with didn't appear to know exactly what the issue is and it seems like the next default solution is to send new equipment. We'll see what happens.
- vkdelta
  NETGEAR Employee Retired
  Jul 16, 2021
  actually, there is noise in line which is causing T3 timeouts.
  you should get internet service but it will go out momentary when there are T3 timeouts.
  
  US power is on the higher side as well.
  you can try renting the modem and almost certain will see the same issue. you can ask them to fix the problem.
  - mattoram
    Tutor
    Jul 17, 2021
    The Xfinity/Comcast technician came out yesterday and tested the signal and connections, and said everything was fine. Neither Netgear or Xfinity asked to look at the logs or modem parameters. It's frustrating because I don't think they really know how to find and fix this issue. I would happily pay a qualifed person to diagnose and fix this. I won't be able to get anyone out this weekend, so I'll wait for the new modem and install it on Tuesday and see if anything changes. If it works great, if not, I'll have to find someone that knows what they're doing or learn it myself. I'm an engineer and I'm sure I can eventually figure it out but I have nearly no knowledge of any of this, at this time.

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Netgear cm 1200 Intermittent connection