I've had the exact same experience for the last 4-5 months. My MB8600 was solid for 6 months until Comcast upgraded the lines outside to fiber last summer. Since then, the MB8600 locks up regularly up to 2-3 times a day. I had techs come out but they say signals are good. The problem is that they are good until they randomly jump up or down +/- 8db. I've gotten the same story from Motorola about the firmware bug, but I haven't seen Comcast push anything out since the problem started (22.214.171.124).
I've tried the Comcast rental (at the request of the tech) and it was much more stable, but it would still lock up occasionally. I've had comcast internet with my own modem for 15+ years and never had problems like this.
It would be great if someone form Comcast could actually acknowldge the problem with the MB8600 and tell me if it is ever going to be fixed.
The problem is that they are good until they randomly jump up or down +/- 8db.
That's not supossed to happen. Something intermittent is going on. Do the upstream power power levels also fluctuate intermittently ?
I've gotten the same story from Motorola about the firmware bug, but I haven't seen Comcast push anything out since the problem started (126.96.36.199).
FWIW, fluctuating signal strengths are not caused by firmware problems. It's a line / connection quality problem somewhere.
I've tried the Comcast rental (at the request of the tech) and it was much more stable, but it would still lock up occasionally.
Some modems are more tolerant of signal problems than are others.
I've been having issues with my MB8600 locking up almost daily since comcast upgraded the lines to fiber in the neighborhood several months ago. Before that, the MB8600 ran perfectly for over 6 months. I've had multiple techs come out and change out coax and check levels with no effect. I've had the exact same expereince as was documented in this post including being told this is a known issue with comcast and the mb8600:
What I have manged to determine is that there seems to be two distinct operating levels on the line that randomly change, sometimes multiple times a day, sometime it will be constant for several days. Both power levels seem to work but when they change (+/- 7db) it causes errors and the modem to hang requiring a manual reboot as its webpage is unaccessible.
I've attached screenshots of the two levels. I've be told this shouldn't happen but the levels do work when static. I've tried just about everthing possible to figure out a soultion, but I'm very confident the problem occurs from whatever is causing the power levels to change. I have noticed this pattern since the very beginning of the issue.
Sorry, I did not get a notification of your reply. I agree with ALL your comments. It's exactly what I have told Comcast but they don't seem to be able to escalate it to anyone that can assist. I just created another post with screeshots of the signal changes.
Please let me know if you can help push this in anyway. Thanks
It looks like you have an intermittent "cable tilt" problem going on in the downstream channels.
I'm going to escalate your ongoing issue to the Comcast corporate employees that are available to these boards. You should get a reply here in your topic. Good luck !
lnorris7, thanks for reaching out about your signal level concerns. Let's take a closer look. Please send me a private message with your name for additional help.