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Forum Discussion
CM1200 upstream led blinking continuosly.
3 of 4 upstream channels not working. Reset to factory default no help. Seems to be common issue with this model.
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.
Be sure to power OFF the modem for 1 minute them back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853
| requency 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. | |
|
Startup Procedure
| Procedure | Status | Comment |
| Acquire Downstream Channel | 765000000 Hz | Locked |
| Connectivity State | OK | Operational |
| Boot State | OK | Operational |
| Security | Enabled | BPI+ |
| IP Provisioning Mode | Honor MDD | honorMdd(4) |
Downstream Bonded Channels (Partial Service)
| Channel | Lock Status | Modulation | Channel ID | Frequency | Power | SNR | Correctables | Uncorrectables |
| 1 | Locked | QAM256 | 32 | 765000000 Hz | 3.6 dBmV | 43.3 dB | 0 | 0 |
| 2 | Locked | QAM256 | 1 | 579000000 Hz | 4.6 dBmV | 43.7 dB | 0 | 0 |
| 3 | Locked | QAM256 | 2 | 585000000 Hz | 4.5 dBmV | 43.7 dB | 0 | 0 |
| 4 | Locked | QAM256 | 3 | 591000000 Hz | 4.9 dBmV | 43.8 dB | 0 | 0 |
| 5 | Locked | QAM256 | 4 | 597000000 Hz | 4.3 dBmV | 43.5 dB | 0 | 0 |
| 6 | Locked | QAM256 | 5 | 603000000 Hz | 4.5 dBmV | 43.6 dB | 0 | 0 |
| 7 | Locked | QAM256 | 6 | 609000000 Hz | 4.5 dBmV | 43.6 dB | 0 | 0 |
| 8 | Locked | QAM256 | 7 | 615000000 Hz | 4.1 dBmV | 43.4 dB | 0 | 0 |
| 9 | Locked | QAM256 | 8 | 621000000 Hz | 4.5 dBmV | 43.6 dB | 0 | 0 |
| 10 | Locked | QAM256 | 9 | 627000000 Hz | 3.9 dBmV | 43.4 dB | 0 | 0 |
| 11 | Locked | QAM256 | 10 | 633000000 Hz | 4 dBmV | 43.5 dB | 0 | 0 |
| 12 | Locked | QAM256 | 11 | 639000000 Hz | 3.9 dBmV | 43.4 dB | 0 | 0 |
| 13 | Locked | QAM256 | 12 | 645000000 Hz | 3.7 dBmV | 43.3 dB | 0 | 0 |
| 14 | Locked | QAM256 | 13 | 651000000 Hz | 4.1 dBmV | 43.5 dB | 0 | 0 |
| 15 | Locked | QAM256 | 14 | 657000000 Hz | 3.6 dBmV | 43.3 dB | 0 | 0 |
| 16 | Locked | QAM256 | 15 | 663000000 Hz | 3.9 dBmV | 43.4 dB | 0 | 0 |
| 17 | Locked | QAM256 | 16 | 669000000 Hz | 3.8 dBmV | 43.4 dB | 0 | 0 |
| 18 | Locked | QAM256 | 17 | 675000000 Hz | 3.6 dBmV | 42.5 dB | 0 | 0 |
| 19 | Locked | QAM256 | 18 | 681000000 Hz | 3.7 dBmV | 43.3 dB | 0 | 0 |
| 20 | Locked | QAM256 | 19 | 687000000 Hz | 3.5 dBmV | 43.2 dB | 0 | 0 |
| 21 | Locked | QAM256 | 20 | 693000000 Hz | 3.6 dBmV | 43.3 dB | 0 | 0 |
| 22 | Locked | QAM256 | 21 | 699000000 Hz | 3.4 dBmV | 43.3 dB | 0 | 0 |
| 23 | Locked | QAM256 | 22 | 705000000 Hz | 3.7 dBmV | 43.3 dB | 0 | 0 |
| 24 | Locked | QAM256 | 23 | 711000000 Hz | 3.4 dBmV | 43.1 dB | 0 | 0 |
| 25 | Locked | QAM256 | 24 | 717000000 Hz | 3.4 dBmV | 43.2 dB | 0 | 0 |
| 26 | Locked | QAM256 | 25 | 723000000 Hz | 3.5 dBmV | 43.3 dB | 0 | 0 |
| 27 | Locked | QAM256 | 26 | 729000000 Hz | 3.2 dBmV | 43 dB | 0 | 0 |
| 28 | Locked | QAM256 | 27 | 735000000 Hz | 3.9 dBmV | 43.4 dB | 0 | 0 |
| 29 | Locked | QAM256 | 28 | 741000000 Hz | 3 dBmV | 42.9 dB | 0 | 0 |
| 30 | Locked | QAM256 | 29 | 747000000 Hz | 3.4 dBmV | 43.1 dB | 0 | 0 |
| 31 | Locked | QAM256 | 30 | 753000000 Hz | 3.2 dBmV | 43.1 dB | 0 | 0 |
| 32 | Locked | QAM256 | 31 | 759000000 Hz | 3.1 dBmV | 43 dB | 0 | 0 |
Upstream Bonded Channels (Partial Service)
| Channel | Lock Status | US Channel Type | Channel ID | Symbol Rate | Frequency | Power |
| 1 | Locked | ATDMA | 1 | 5120 Ksym/sec | 17600000 Hz | 46.5 dBmV |
| 2 | Not Locked | Unknown | 2 | 0 Ksym/sec | 17600000 Hz | 0.0 dBmV |
| 3 | Not Locked | Unknown | 3 | 0 Ksym/sec | 30400000 Hz | 0.0 dBmV |
| 4 | Not Locked | Unknown | 4 | 0 Ksym/sec | 36800000 Hz | 0.0 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 | 159 | 300000000 Hz | 5.0 dBmV | 43.9 dB | 1108 ~ 2987 | 214435541 | 12816736 | 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:Thu May 27 14:39:46 2021System Up Time:01:53:04
New cable to house, modem is located where cable inters the house.
Spectrum Tech pointed out the blocked upstreem channels.
numerous dropoffs throughout the day.
Has the modem been factory reset since installation.
What is the ISP speed package up and down you pay for.
Ya your upstream channels are not being locked in, for me on a 1Gb/50Mbps service I have 4 upstream channels locked in i believe.
If yours isn't locking in, i'd get the ISP to send out a tech on site and have them take a closer look. Any splitters on the line? Bad cabling or terminatior or splitters can cause this as well.
Be aware that Spectrum is notorious for not doing anything with user owned modems. There very hard to work with. So you may not get any great help. They probably won't update the modems FW. Which FW version is on currently on the modem?
If you seem to get no help with spectrum, you may want to rent one of there modems for short period of time, see if there modems do the same thing or not. If they do they they would have to correct the issue. Then you could probably put the CM modem back online.