CM1200 upstream led blinking continuosly.

Question

3 of 4 upstream channels not working. Reset to factory default no help. Seems to be common issue with this model.

FURRYe38 · Answer

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

rwhit1 · Answer

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.Starting Frequency &nbsp;Startup Procedure Procedure Status Comment Acquire Downstream Channel765000000 HzLockedConnectivity StateOKOperationalBoot StateOKOperationalSecurityEnabledBPI+IP Provisioning ModeHonor MDDhonorMdd(4)&nbsp;Downstream Bonded Channels (Partial Service)Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1LockedQAM25632765000000 Hz3.6 dBmV43.3 dB002LockedQAM2561579000000 Hz4.6 dBmV43.7 dB003LockedQAM2562585000000 Hz4.5 dBmV43.7 dB004LockedQAM2563591000000 Hz4.9 dBmV43.8 dB005LockedQAM2564597000000 Hz4.3 dBmV43.5 dB006LockedQAM2565603000000 Hz4.5 dBmV43.6 dB007LockedQAM2566609000000 Hz4.5 dBmV43.6 dB008LockedQAM2567615000000 Hz4.1 dBmV43.4 dB009LockedQAM2568621000000 Hz4.5 dBmV43.6 dB0010LockedQAM2569627000000 Hz3.9 dBmV43.4 dB0011LockedQAM25610633000000 Hz4 dBmV43.5 dB0012LockedQAM25611639000000 Hz3.9 dBmV43.4 dB0013LockedQAM25612645000000 Hz3.7 dBmV43.3 dB0014LockedQAM25613651000000 Hz4.1 dBmV43.5 dB0015LockedQAM25614657000000 Hz3.6 dBmV43.3 dB0016LockedQAM25615663000000 Hz3.9 dBmV43.4 dB0017LockedQAM25616669000000 Hz3.8 dBmV43.4 dB0018LockedQAM25617675000000 Hz3.6 dBmV42.5 dB0019LockedQAM25618681000000 Hz3.7 dBmV43.3 dB0020LockedQAM25619687000000 Hz3.5 dBmV43.2 dB0021LockedQAM25620693000000 Hz3.6 dBmV43.3 dB0022LockedQAM25621699000000 Hz3.4 dBmV43.3 dB0023LockedQAM25622705000000 Hz3.7 dBmV43.3 dB0024LockedQAM25623711000000 Hz3.4 dBmV43.1 dB0025LockedQAM25624717000000 Hz3.4 dBmV43.2 dB0026LockedQAM25625723000000 Hz3.5 dBmV43.3 dB0027LockedQAM25626729000000 Hz3.2 dBmV43 dB0028LockedQAM25627735000000 Hz3.9 dBmV43.4 dB0029LockedQAM25628741000000 Hz3 dBmV42.9 dB0030LockedQAM25629747000000 Hz3.4 dBmV43.1 dB0031LockedQAM25630753000000 Hz3.2 dBmV43.1 dB0032LockedQAM25631759000000 Hz3.1 dBmV43 dB00&nbsp;Upstream Bonded Channels (Partial Service)Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1LockedATDMA15120 Ksym/sec17600000 Hz46.5 dBmV2Not LockedUnknown20 Ksym/sec17600000 Hz0.0 dBmV3Not LockedUnknown30 Ksym/sec30400000 Hz0.0 dBmV4Not LockedUnknown40 Ksym/sec36800000 Hz0.0 dBmV5Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV6Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV7Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV8Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV&nbsp;Downstream OFDM ChannelsChannel LockStatus Modulation /Profile ID ChannelID Frequency Power SNR /MER Active SubcarrierNumber Range UnerroredCodewords CorrectableCodewords UncorrectableCodewords 1Locked0 ,1 ,2159300000000 Hz5.0 dBmV43.9 dB1108 ~ 29872144355411281673602Not Locked000 Hz0 dBmV0.0 dB0 ~ 4095000&nbsp;Upstream OFDMA ChannelsChannel Lock Status Modulation / Profile ID Channel ID Frequency Power 1Not Locked000 Hz0 dBmV2Not Locked000 Hz0 dBmV&nbsp;Extended Upstream Transmit Power Enable Extended Upstream Transmit Power&nbsp;Current System Time:Thu May 27 14:39:46 2021System Up Time:01:53:04

rwhit1 · Answer

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.

FURRYe38 · Answer

Has the modem been factory reset since installation.&nbsp;What is the ISP speed package up and down you pay for.&nbsp;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.&nbsp;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.&nbsp;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?&nbsp;&nbsp;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.&nbsp;

Forum Discussion

CM1200 upstream led blinking continuosly.

4 Replies

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)

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

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

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

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