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Critical errors with Netgear CM500

Contributor

Critical errors with Netgear CM500

018-2-26, 19:02:06 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.0;
2018-2-26, 19:02:12 Warning (5) MDD message timeout;CM-MAC=XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.0;
2018-2-26, 19:02:13 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.0;
2018-2-26, 19:04:13 Warning (5) MDD message timeout;CM-MAC=dc:ef:09:7d:c4:30;CMTS-MAC=dc:eb:94:b5:3d:cc;CM-QOS=1.1;CM-VER=3.0;
2018-2-26, 19:04:20 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=XX:XX:XX:XXCMTS-MAC=XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.0;
2018-2-26, 19:04:24 Warning (5) MDD message timeout;CM-MAC=XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.0;

 

I'm getting all of those error after reboot. I also have fw that is newer than Netgear has. Can anybody help?

 

I also get lots of unrecoverables. Last time I had this Comcast denied any issues, but then I saw multiple Comcast trucks by the cable box and it was fixed after that.

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 9 543000000 Hz 1 dBmV 40.1 dB 21313 6960
2 Locked QAM256 13 567000000 Hz 1.4 dBmV 40.1 dB 3 0
3 Locked QAM256 14 573000000 Hz 1.4 dBmV 40.1 dB 4 0
4 Locked QAM256 15 579000000 Hz 1.2 dBmV 40.1 dB 67 330
5 Locked QAM256 16 585000000 Hz -1.1 dBmV 39.2 dB 20 0
6 Locked QAM256 1 489000000 Hz 1.1 dBmV 40.7 dB 6 0
7 Locked QAM256 2 495000000 Hz 1 dBmV 40.4 dB 10 0
8 Locked QAM256 3 507000000 Hz 1.1 dBmV 39.6 dB 15 0
9 Locked QAM256 4 513000000 Hz 0.8 dBmV 40.3 dB 12 0
10 Locked QAM256 5 519000000 Hz 0.6 dBmV 40.1 dB 368 1707
11 Locked QAM256 6 525000000 Hz 0.7 dBmV 40.1 dB 3390 14714
12 Locked QAM256 7 531000000 Hz 0.7 dBmV 40.1 dB 21237 33380
13 Locked QAM256 8 537000000 Hz 0.8 dBmV 40.1 dB 61412 27794
14 Locked QAM256 10 549000000 Hz 1.2 dBmV 40.1 dB 34945 16773
15 Locked QAM256 11 555000000 Hz 1.3 dBmV 40.1 dB 42644 17771
16 Locked QAM256 12 561000000 Hz 1.3 dBmV 40 dB 3403 14028
Expert

Re: Critical errors with Netgear CM500

Depending on the total *uptime* of the modem, those *uncorrectable* bit errors may be quite low. The downstream signal stat figures are good. What do the upstream power level figures look like ? Are you actually experiencing any connectivity issues ?

Contributor

Re: Critical errors with Netgear CM500

Here is the upstream

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 1 5120 Ksym/sec 37800000 Hz 49.6 dBmV
2 Locked ATDMA 2 5120 Ksym/sec 31400000 Hz 49.6 dBmV
3 Locked ATDMA 3 5120 Ksym/sec 25000000 Hz 48.9 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 18600000 Hz 49 dBmV

 

It seems I'm. I have 2 wifi routers. My setup is Netgear R7000 as the main router and Asus 68U as a media bridge. It seems that I'm experiencing internet drop-offs. I thought maybe R7000 is having issues so I re-configured 68U to be the main router, but I'm still having the same issues. btw fw on CM500 has changed from V1.01.08 to V1.01.09 in the last couple of months. 

 

 

Expert

Re: Critical errors with Netgear CM500

The upstream power is borderline / high and may be intermittently fluctuating even higher out of spec. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.


Contributor

Re: Critical errors with Netgear CM500

There is only one splitter for phone modem and internet modem. That splitter was installed by Comcast tech about 4 years ago. I have another splitter to try, but the same setup has been working fine for years. I will also check the box outside where the house wires come into the house, but I bet it is the central box for multiple houses like it was one time before. This behavior usually happens in the winter when it gets really cold.

 

I could try to use phone 722G modem for both and see if it gets better. Question. Can I provision 722G without support and back to CM500? I have 150/5 and I know 722G can't handle that speed.

Expert

Re: Critical errors with Netgear CM500

It's more likely to be a line problem than a modem problem. And if you used the 722 not too long ago, it may still have its provisioning. Give it a try. If it won't connect, you'll need to call.