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Forum Discussion
[CM1200] Constant Internet Drop on Spectrum
Hello, A few days ago I decided to purchase my own modem. I originally purchased the Arris SB8200. 24 hours after activation I started having my connection drop every so often; it would come back...
If the ISP modem works and the CM doesn't after all that, I would return the CM modem or get it replaced with another and try again.
Mexicant11 wrote:
Please update when you have an answer. I too am having the same problems after choosing to upgrade my modem. I've had three service calls with three different text coming out. The last tech today, replaced all the lines, I mean every line coming down from the pole into my house. Sobline integrity is not the issue. He could not figure out what was wrong. On 3 out of 4 upstream channels had no signal.the only solution was to provide their own 3.1 modem. I would rather use my CM1200. So any additional info would be helpful.
I am having the same issue for weeks now. Have just requested the 2nd tech call with ISP. Beyond maddening. The issue started after the news about the Netgear security vulnerability. I’m planning to return this modem and switch brands.
What security vulnerability would that be?
Have the ISP check the signal and line quality UP to the modem.
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.
LindaMc wrote:
I am having the same issue for weeks now. Have just requested the 2nd tech call with ISP. Beyond maddening. The issue started after the news about the Netgear security vulnerability. I’m planning to return this modem and switch brands.US is partial service.
You only have 1 US locked and there are T3 timeouts on 3 US.
Did you have logs with SB8200? Does it show the same issue?
do you have screenshots with charter leased modem? (I dont think they provide GUI access and you may not be able to see even if there is a problem or not)
I'm also having this problem. I bought the cable model in October and it's been fine until now. Today it dropped the Internet 3 or 4 times. Nothing has changed (unless it updated itself with new code). It's hardware 1.01 and firmware V2.02.03. The log includes:
RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:42:65:18;CMTS-MAC=00:a5:bf:0f:ea:ad;CM-QOS=1.1;CM-VER=3.1;
Dynamic Range Window violation
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=08:36:c9:42:65:18;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Honoring MDD; IP provisioning mode = IPv4
There's more in the attached logfile. Any ideas why it should start having problems now?
Thanks,
Chris
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
choll wrote:I'm also having this problem. I bought the cable model in October and it's been fine until now. Today it dropped the Internet 3 or 4 times. Nothing has changed (unless it updated itself with new code). It's hardware 1.01 and firmware V2.02.03. The log includes:
RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:42:65:18;CMTS-MAC=00:a5:bf:0f:ea:ad;CM-QOS=1.1;CM-VER=3.1;
Dynamic Range Window violation
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=08:36:c9:42:65:18;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Honoring MDD; IP provisioning mode = IPv4
There's more in the attached logfile. Any ideas why it should start having problems now?
Thanks,
Chris
