user_daw312's profile

Contributor

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226 Messages

Wednesday, March 18th, 2026 3:53 PM

Modem lost OFDMA Channel!

We had some pretty bad storms 2 days ago in the Maryland area. My Comcast network and Netgear CM3000 have fared fine. But today, I checked on a (Comcast) neighbor's modem stats (also a CM3000 modem), and I saw something strange - they have lost their OFDMA upstream channel! Their plan speeds are either 1GB/100M or 1.2GB/200M, something like that. Historically their modem power/SNR/error logs, etc. has been pretty clean.

I happened to have older house logs, on Mar 12 their modem reported:

Upstream OFDMA Channels

Channel LockedStatus ProfileID ChannelID Frequency Power

1 Locked 12 ,13 41 36200000 Hz 40.5 dBmV

2 Not Locked 0 0 0 Hz 0 dBmV

Yet this morning it shows as this:

Upstream OFDMA Channels

Channel LockedStatus ProfileID ChannelID Frequency Power

1 Not Locked 0 0 0 Hz 0 dBmV

2 Not Locked 0 0 0 Hz 0 dBmV

Our bad storms were Mar 16. How should I proceed as they have asked for my help - power cycle modem? Wait a few days for it to correct? call Comcast? Other? Is there a way I should try getting it re-provisioned?

PS - we are on different CMTS-MAC addresses, I assume different node/tap. Their log had a burst of T3 errors on Mar 17, no T4s, no modem restarts, etc. Normally their modem power levels/stats/errors are pretty good.

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Accepted Solution

Expert

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116.7K Messages

58 minutes ago

Yes. First try power-cycling / re-starting the device by unplugging it for a minute ? Still no joy ? Try hard resetting the device to factory defaults by pressing and holding in the recessed reset button on the rear for 30 seconds.

Contributor

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226 Messages

Thanks @EG . You've been around helping me and others for a long time! Greatly appreciated.

If I need to reset to defaults, just plug it in and go through activation in the app like it' a brand new modem being put online?

Expert

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116.7K Messages

46 minutes ago

It's my pleasure ! Resetting it to defaults should not cause it to lose its provisioning with the system. Just reset it while it is plugged in and then let it do its thing. It should re-sync in five to fifteen minutes or so.

Contributor

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226 Messages

@EG thanks. I will be doing this at my daughter's house, I have user/pw access to her modem web page and router user/pw, but don't have her Comcast acct user/pw. I can get that if needed. But to be sure I understand, it sounds like I don't need anything in the app, just press the reset button, and wait for it to come online?

Expert

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116.7K Messages

@user_daw312​ wrote;

it sounds like I don't need anything in the app, just press the reset button, and wait for it to come online?

Correct. Good luck ! Please post back with how things turn out.

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