SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing

Hello,

My modem is a Motorola MB8611 and the problems began after an upgrade (speed) in service. I see numerous posts about this issue and believe I have issues that need to be escalated. The info I have is as follows:

Cable Specification Version	DOCSIS 3.1
Hardware Version	V1.0
Software Version	8611-19.2.18
Cable Modem MAC Address
Cable Modem Serial Number
CM Certificate	Installed
	Prod_19.2_d31

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;

No Ranging Response received - T3 time-out;

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Freq. (MHz)	Pwr (dBmV)	SNR (dB)	Corrected	Uncorrected
1	Locked	QAM256	13	507.0	3.0	42.1	0	0
2	Locked	QAM256	1	417.0	3.2	42.4	0	0
3	Locked	QAM256	2	423.0	3.2	42.4	0	0
4	Locked	QAM256	3	429.0	3.4	42.6	0	0
5	Locked	QAM256	4	435.0	3.4	42.6	0	0
6	Locked	QAM256	5	459.0	3.2	42.3	0	0
7	Locked	QAM256	6	465.0	3.2	42.3	0	0
8	Locked	QAM256	7	471.0	3.2	42.3	0	0
9	Locked	QAM256	8	477.0	3.1	42.3	0	0
10	Locked	QAM256	9	483.0	3.1	42.2	0	0
11	Locked	QAM256	10	489.0	3.2	42.3	0	0
12	Locked	QAM256	11	495.0	3.1	42.2	0	0
13	Locked	QAM256	12	501.0	3.0	42.1	0	0
14	Locked	QAM256	14	513.0	2.8	42.0	0	0
15	Locked	QAM256	15	519.0	2.8	42.0	0	0
16	Locked	QAM256	16	525.0	2.8	41.8	0	0
17	Locked	QAM256	17	531.0	2.9	42.1	0	0
18	Locked	QAM256	18	537.0	2.8	42.0	0	0
19	Locked	QAM256	19	543.0	2.7	41.8	0	0
20	Locked	QAM256	20	549.0	2.8	41.9	0	0
21	Locked	QAM256	21	555.0	2.8	41.8	0	0
22	Locked	QAM256	22	561.0	2.7	41.8	0	0
23	Locked	QAM256	23	567.0	2.8	41.8	0	0
24	Locked	QAM256	24	573.0	2.8	41.8	0	0
25	Locked	QAM256	25	579.0	2.8	41.7	0	0
26	Locked	QAM256	26	585.0	2.7	41.7	0	0
27	Locked	QAM256	27	591.0	2.9	41.8	0	0
28	Locked	QAM256	28	597.0	2.8	41.8	0	0
29	Locked	QAM256	29	603.0	2.7	41.6	0	0
30	Locked	QAM256	30	609.0	2.7	41.8	0	0
31	Locked	QAM256	31	615.0	2.7	41.6	0	0
32	Locked	OFDM PLC	33	690.0	3.2	41.6	21613698	0

Upstream Bonded Channels

Channel	Lock Status	Channel Type	Channel ID	Symb. Rate (Ksym/sec)	Freq. (MHz)	Pwr (dBmV)
1	Locked	SC-QAM	41	5120	17.3	46.0
2	Locked	SC-QAM	42	5120	23.7	46.0
3	Locked	SC-QAM	43	5120	30.1	45.5
4	Locked	SC-QAM	44	5120	36.5	45.0

Please advise next steps. I can experience an outage or service interruption several times a day.

Thanks

Responses

EG

Expert

•

110.2K Messages

4 years ago

That stats were ok / in spec at that snapshot in time. please post the error log entries in their entirety (copy and paste them, don't post a screenshot) but redact the CM MAC and the CMTS MAC addresses for your privacy. They are considered to be personal information. Personally identifying information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically.

0

CCEthan

Official Employee

•

1.4K Messages

4 years ago

Hi, @user_kdseatac2021. I did a check on everything and didn't find any issues. The signal is great and no increase in T3 timeouts or any area issues that would lead to dropouts. I see there was a reset 2 days ago. Are you still having issues?

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EG

Expert

•

110.2K Messages

4 years ago

@user_kdseatac2021

I'd still like to see the error log entries. As requested, please post them here in public view.

0

U

user_kdseatac2021

Visitor

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3 Messages

4 years ago

Hello EG & Ethan,

I have been away for several days and will post the requested info. I appreciate the prompt reply. To answer Ethan's question, yes we are still having line drops. If it helps the issue began when we upgraded to 800mbs service.

Thank you again

1

0

CCAbbie

Problem Solver

•

1.4K Messages

@user_kdseatac2021 Hello, I am sorry to hear you are continuing to have issues.

I'd like to get your account pulled up to see if I can find any issues on my end.

Please send a private message by clicking the direct messaging chat icon in the upper right corner of the page, click on the pen and paper icon, then enter “Xfinity Support” in the “To” section. Please include your name and address and I'll be happy to help.

I no longer work for Comcast.

4 years ago

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U

user_kdseatac2021

Visitor

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3 Messages

3 years ago

Dear all,

Following is a copy paste as requested. Please advise next steps.

Time Not Established	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;
09:16:05 Tue Nov 9 2021	Critical (3)	TFTP failed - Request sent - No Response;;CM-QOS=1.1;CM-VER=3.1;
09:16:05 Tue Nov 9 2021	Critical (3)	TFTP Request Retries exceeded, CM unable to register
09:16:55 Tue Nov 9 2021	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
09:18:15 Tue Nov 9 2021	Critical (3)	TFTP failed - Request sent - No Response;;CM-QOS=1.1;CM-VER=3.1;
09:18:16 Tue Nov 9 2021	Critical (3)	TFTP Request Retries exceeded, CM unable to register
09:18:23 Tue Nov 9 2021	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
09:19:11 Tue Nov 9 2021	Critical (3)	TFTP failed - Request sent - No Response;;CM-QOS=1.1;CM-VER=3.1;
09:19:11 Tue Nov 9 2021	Critical (3)	TFTP Request Retries exceeded, CM unable to register
09:19:20 Tue Nov 9 2021	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
09:20:06 Tue Nov 9 2021	Critical (3)	TFTP failed - Request sent - No Response;;CM-QOS=1.1;CM-VER=3.1;
09:20:06 Tue Nov 9 2021	Critical (3)	TFTP Request Retries exceeded, CM unable to register
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;C;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;C;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
13:31:26 Sat Nov 13 2021	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;;CM-QOS=1.1;CM-VER=3.1;

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U

user_075553

Visitor

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2 Messages

3 years ago

Hi,

I am having this same issue. My modem stats and event log look very similar to yours. Was this resolved? If so, what was the resolution?

Thank you!

1

0

EG

Expert

•

110.2K Messages

@user_075553

Please create a new topic of your own here on this board detailing your issue. Thanks. The original poster has not returned. 3-month-old dead thread now being closed.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer! tick

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer! tick

3 years ago

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user_kdseatac2021

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing

EG

CCEthan

EG

user_kdseatac2021

CCAbbie

user_kdseatac2021

user_075553

EG

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