CM1000V2 and comcast, CM1000 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol

[PeteH8sXfinity]

I've been battling disconnects, from 2-10 a day, packet loss, slow speeds. Playing World of Warcraft or Call of Duty becomes unplayable due to normal 50-60ms speeds going to 1100-2000ms+. 

I've spent so many hours both online and telephone chat with Xfinity tech support. The last time a tech came out he replaced 85' of line from the pole to my home. It was ok for a couple days then right back to the same issues. 

I've been keeping logs over the last few days. My time is off by 6 hours on the modem.

2022-10-19, 21:59:18 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A;
2022-10-19, 21:59:08 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A;
2022-10-19, 21:56:54 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:56:37 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:54:36 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:54:28 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:53:19 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:49:04 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:48:33 Warning (5) MDD message timeout;CM
2022-10-19, 21:42:23 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr
2022-10-19, 21:42:19 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A
2022-10-19, 21:41:07 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:41:01 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; ;
2022-10-19, 21:37:41 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A
2022-10-19, 21:37:30 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:35:16 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:35:04 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:31:53 Notice (6) CM-STATUS message sent. Event Type Code: 22; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:28:56 Notice (6) CM-STATUS message sent. Event Type Code: 20; Chan ID: 48; DSID: N/A; MAC Addr: N/A; ;
2022-10-19, 21:20:15 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:20:12 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:15:38 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:11:44 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 21:11:05 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 20:58:52 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 20:58:32 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A;
2022-10-19, 20:58:04 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
Time Not Established Critical (3) No Ranging Response received - T3 time-out;Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-
2022-10-19, 20:56:54 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;

[FURRYe38]

Please post a copy and paste of the modems connection status page.
https://kb.netgear.com/30007/How-do-I-obtain-the-cable-connection-information-from-a-NETGEAR-cable-m...

Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 
What is the brand and model of the host wifi router connected to the modem?

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 then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

[PeteH8sXfinity]

[PeteH8sXfinity]

I'm going to go ahead and order new cables, should I go higher than CAT6 or will that suffice? I want to best perfomance available.

Thank you!

[FURRYe38]

Your main channels have some correct and un-correcables. 

I see the OFDMA channel has tons. This should be near zeros. something the ISP should help you resolve. Something to check the coax cable line and remove any splitters. Check all jack fittings and such. 
Have the ISP check the signal up to the modem as well. Power on the line is a bit on the low side but in spec. 

CAT6 UTP is fine. 

What is the distance between the modem and router? 
What brand and model router are you using with the CM modem? 

[PeteH8sXfinity]

Distance between modem and router is about 2.5 feet. Model of router is: tp-link AX1500 Wi-Fi 6 router.

[PeteH8sXfinity]

Archer AX1500

AX1500 Wi-Fi 6 Router

[FURRYe38]

Lets increase the distance to 6 feet between the modem and router. 

[PeteH8sXfinity]

Ok so the tech came out from Xfinity. Found a small "kink" in my cable (didn't looks like much tbh). Also removed a splitter. Was stable all of yesterday after he left. Today it is back to normal, stable then for no reason speeds drop and online gaming pings go up to 600-2000ms. I explained to him and showed him that my "time on the modem" is 9 hours ahead of where it should be. He said that does not matter that I'm getting a perfect signal to my modem, and if I continue having issues it's the Netgear modem and that I should consider renting one from xfinity.

Replaced the ethernets to Cat6 and moved the modem. 

Todays error log :2022-10-21, 20:05:33 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 28 31 32 34 36 37 38 39 40 41 42 43 44 45 46 47 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-
2022-10-21, 20:05:32 Notice (6) CM-STATUS message sent. Event Type Code: 23; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;
2022-10-21, 20:05:25 Warning (5) MDD message timeout;CM-
2022-10-21, 20:02:01 Notice (6) CM-STATUS message sent. Event Type Code: 23; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM
2022-10-21, 20:01:46 Notice (6) CM-STATUS message sent. EveCM-MAC=08:36:c9:ce:1a:80;CMTS-MAC=
2022-10-21, 20:01:45 Notice (6) CM-STATUS message sent. Event Type Code: 23; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 20:01:30 Notice (6) CM-STATUS message sent. Event Type Code: 22; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 20:01:30 Notice (6) CM-STATUS message sent. Event Type Code: 23; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 20:01:14 Notice (6) CM-STATUS message sent. Event Type Code: 22; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 20:01:13 Notice (6) CM-STATUS message sent. Event Type Code: 23; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 20:01:02 Notice (6) CM-STATUS message sent. Event Type Code: 22; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC
2022-10-21, 19:59:04 Notice (6) CM-STATUS message sent. Event Type Code: 23; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 19:58:50 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=;
2022-10-21, 19:58:49 Notice (6) CM-STATUS message sent. Event Type Code: 23; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=;
2022-10-21, 19:58:47 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 28 31 32 34 36 37 38 39 40 41 42 43 44 45 46 47 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=0
2022-10-21, 19:58:46 Warning (5) MDD message timeout;CM-MAC=
2022-10-21, 19:58:46 Notice (6) CM-STATUS message sent. Event Type Code: 1; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 19:58:46 Warning (5) MDD message timeout;CM-MAC=
2022-10-21, 19:57:59 Notice (6) CM-STATUS message sent. Event Type Code: 1; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 19:57:44 Warning (5) MDD message timeout;CM-MAC=
2022-10-21, 19:57:39 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 19:57:38 Warning (5) MDD message timeout;CM-MAC=
2022-10-21, 19:57:29 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 19:57:16 Warning (5) MDD message timeout;CM-MAC=
2022-10-21, 19:57:00 Notice (6) CM-STATUS message sent. Event Type Code: 20; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=;
2022-10-21, 19:56:43 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=
2022-10-21, 19:56:40 Notice (6) CM-STATUS message sent. Event Type Code: 1; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC
2022-10-21, 19:56:11 Warning (5) MDD message timeout;CM-MAC=
2022-10-21, 19:55:46 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC
2022-10-21, 19:55:27 Warning (5) MDD message timeout;CM-MAC=CMTS-MAC=
2022-10-21, 19:55:11 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;C
2022-10-21, 19:55:00 Warning (5) MDD message timeout;CM-MAC;CMTS-MAC=
2022-10-21, 19:54:22 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2 3.;CM-MAC=
2022-10-21, 19:52:40 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; 2022-10-21, 19:47:21 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1
2022-10-21, 19:47:19 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=
2022-10-21, 19:46:01 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=
2022-10-21, 19:42:19 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=
2022-10-21, 19:41:44 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=
2022-10-21, 19:41:40 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2.;CM-MAC=

[FURRYe38]

Might do a factory reset on the CM modem and set it up from scratch. 

Though those logs are mostly for channel 48 and OFDMA notices and nothing critical. Possible something on the ISP side that doesn't service OFDMA maybe. Other wise looks ok. 

Might ask the ISP to remove the modems association with there service. Then re-add it and ensure it's go the right config file sent down. 

Try connecting to the modem only with a wired PC for a duration to see if problem is seen here as well. If not, then possible your wifi router could be at play here. Tthen you might try and change this item out and try a different one as well. If the problem still continues, rent the ISP modem for a while and see if the problem continues or not. if not, then possible the CM modem could be faulty. 

[Kitsap]

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@PeteH8sXfinity wrote:

Ok so the tech came out from Xfinity. Found a small "kink" in my cable (didn't looks like much tbh). Also removed a splitter. Was stable all of yesterday after he left. Today it is back to normal, stable then for no reason speeds drop and online gaming pings go up to 600-2000ms. I explained to him and showed him that my "time on the modem" is 9 hours ahead of where it should be. He said that does not matter that I'm getting a perfect signal to my modem, and if I continue having issues it's the Netgear modem and that I should consider renting one from xfinity.

Replaced the ethernets to Cat6 and moved the modem. 

---

Is the system time on your router correct or does it match your modem?

What part of the country do your live in?  Comcast is making a lot of system changes in many areas and have been doing so for several weeks.

What is the firmware version on your modem?

[PeteH8sXfinity]

"Try connecting to the modem only with a wired PC for a duration to see if problem is seen here as well. If not, then possible your wifi router could be at play here"

I did that today with the new Ethernet cables, still the same problems.

[FURRYe38]

I would try one of there modems or find a new CM series modem to try out and see if problems continue. IF they don't then I presume we can call the 1000 faulty. 

[PeteH8sXfinity]

Is the system time on your router correct or does it match your modem? Not sure how to check that.

What part of the country do your live in?  Comcast is making a lot of system changes in many areas and have been doing so for several weeks.  Twain harte. CA

What is the firmware version on your modem? the up to date one listed by Comcast/Xfinity 

Firmware Version

V10.01.07

[PeteH8sXfinity]

Ouch thats $180 down the drain.

[FURRYe38]

Might ask the ISP to remove the modems association with there service. Then re-add it and ensure it's go the right config file sent down. 

If you have a friend or family member with a cable ISP, try the CM at a different location to see if the problem follow would be another suggestion. 

[Kitsap]

 

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@PeteH8sXfinity wrote:

Is the system time on your router correct or does it match your modem? Not sure how to check that.

What part of the country do your live in?  Comcast is making a lot of system changes in many areas and have been doing so for several weeks.  Twain harte. CA

What is the firmware version on your modem? the up to date one listed by Comcast/Xfinity 

Firmware Version

V10.01.07

---

Go to this link:  https://www.tp-link.com/us/support/download/archer-ax1500/ ,  select the appropriate hardware version and download the manual.  If you have never logged in to your router and set the NTP server and time zone, that could be a significant part of your problem.  It would not hurt to do some reading in the manual on how to setup and configure your router.  All of these should be thoroughly explored before you pop out $ for a replacement modem!

[PeteH8sXfinity]

yes time is correct on wi-fi router.

[Kitsap]

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@PeteH8sXfinity wrote:

yes time is correct on wi-fi router.

---

Thanks for the information.

FURRYe38's questions/recommendations should be resolved before you purchase a new modem.