I have this weird issue with one of my MC-88V line cards. The cmts is a uBR7246VXR with 12.2(33)SCG3. I'm not doing anything too fancy, just 4x2 bonded channels per MAC domain. Anyhow here is the problem. On one downstream(C4/1) we have 1 rf-channel that will not come up, the other 3 are up and working fine(42dB SNR). It will start to initialize for a while then go to disabled(DOCSIS LB group). First I though something was stomping on that freq(705) but the spectrum analyzer showed otherwise, no noise or anything when I shut the channel down to check the noise floor. So we swapped all us/ds cables on 4/0 with 4/1 to see if the problem moved with the HFC nodes or stayed local to the port. The problem stayed on 4/1 so I can only imagine it's a line card.
The other thing that is odd is all wideband modems will bond to that channel but the forward SNR on the freq bounces between 41 and as low at 5. No integrated modems will lock on that freq even when forcing it with 'test cable dcc'. I guess my question is, can 1rf channel on a cable interface have problems(hardware) while the other 3 rf-channels work just fine? Has anyone experienced this before?
Thanks in advance!
I had some issues with just one controller before. I think that's because the hardware for each controller is independent within each integrated line card. Why don't you try just configuring a narrow channel using that controller to see if you have an issue in that specific controller?