Purchased a new CM700 and activated (via online) with Comcast. Before I had Arris SB6580 and had download speed of >150 mpbs, now I am getting <90 mpbs with blinking download stream light.Here is a copy of the error logs. Can someone tell me how to fix this blinking downstream light and the errors seeing on the error log? Thanks! Oct 08 2020 02:53:54Error (4)RCS Primary DS FailureOct 08 2020 02:54:11Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:54:23Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:54:26Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:54:26Error (4)RCS Primary DS FailureOct 08 2020 02:54:41Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:54:53Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:54:56Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:54:56Error (4)RCS Primary DS FailureOct 08 2020 02:55:14Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:55:27Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:55:30Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:55:30Error (4)RCS Primary DS FailureOct 08 2020 02:55:46Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:55:59Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:56:02Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:56:02Error (4)RCS Primary DS FailureOct 08 2020 02:56:19Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:56:35Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:56:38Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:56:38Error (4)RCS Primary DS FailureOct 08 2020 02:56:54Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:57:16Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:57:19Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:57:19Error (4)RCS Primary DS FailureOct 08 2020 02:57:34Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:57:47Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:57:50Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:57:50Error (4)RCS Primary DS FailureOct 08 2020 02:58:07Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:58:29Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:58:32Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:58:32Error (4)RCS Primary DS FailureOct 08 2020 02:58:49Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:59:05Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:59:08Critical (3)SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out periodOct 08 2020 02:59:08Error (4)RCS Primary DS FailureOct 08 2020 02:59:25Critical (3)No Ranging Response received - T3 time-outOct 08 2020 02:59:41Warning (5)MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1Oct 08 2020 02:59:44Warning (5)RCS Partial Service

If you mean this... Apply Cancel Frequency start ValueThis field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.Starting Frequency<tabindex=-1>Startup Procedure</tabindex=-1>ProcedureStatusCommentAcquire Downstream Channel663000000 HzLockedConnectivity StateOkOperationalBoot StateOkOperationalSecurityEnabledBPI+IP Provisioning ModeHonor MDDhonorMdd(4)Downstream Bonded Channels (Partial Service)ChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectablesUnCorrectables1LockedQAM 25626555000000 Hz-17.3 dBmV30.0 dB2276940951697342LockedQAM 25627561000000 Hz-10.7 dBmV33.4 dB531221283LockedQAM 25628567000000 Hz-8.5 dBmV35.0 dB1804LockedQAM 25629573000000 Hz-7.7 dBmV30.5 dB2628705LockedQAM 25630579000000 Hz-7.5 dBmV31.6 dB354106LockedQAM 25631585000000 Hz-7.0 dBmV27.8 dB5322743743070737LockedQAM 25632591000000 Hz-7.2 dBmV31.9 dB3518LockedQAM 25633597000000 Hz-7.0 dBmV33.0 dB3209LockedQAM 25634603000000 Hz-6.4 dBmV33.4 dB11010LockedQAM 25635609000000 Hz-6.4 dBmV34.9 dB6111LockedQAM 25636615000000 Hz-6.4 dBmV34.9 dB30012LockedQAM 25637621000000 Hz-5.7 dBmV34.9 dB8013LockedQAM 25638627000000 Hz-6.0 dBmV35.0 dB21014LockedQAM 25639633000000 Hz-5.7 dBmV35.1 dB6015LockedQAM 25640639000000 Hz-6.2 dBmV34.9 dB3016LockedQAM 25641645000000 Hz-6.0 dBmV34.9 dB5017LockedQAM 25642651000000 Hz-6.2 dBmV34.5 dB35018LockedQAM 25643657000000 Hz-6.2 dBmV34.9 dB0019LockedQAM 25644663000000 Hz-6.4 dBmV34.4 dB2020LockedQAM 25645669000000 Hz-6.2 dBmV34.8 dB2021LockedQAM 25646675000000 Hz-6.2 dBmV34.8 dB6022LockedQAM 25647681000000 Hz-5.7 dBmV34.8 dB11023Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0024Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0025Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0026Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0027Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0028Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0029Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0030Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0031Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB0032Not LockedN/AN/A0 Hz0.0 dBmV0.0 dB00Upstream Bonded ChannelsChannelLock StatusUS Channel TypeChannel IDSymbol RateFrequencyPower1LockedATDMA15120 Ksym/sec16400000 Hz43.5 dBmV2LockedATDMA25120 Ksym/sec22800000 Hz44.3 dBmV3LockedATDMA35120 Ksym/sec29200000 Hz44.8 dBmV4LockedATDMA45120 Ksym/sec35600000 Hz45.0 dBmV5LockedATDMA51280 Ksym/sec39600000 Hz42.3 dBmV6Not LockedN/AUnknown0 Ksym/sec0 Hz0.0 dBmV7Not LockedN/AUnknown0 Ksym/sec0 Hz0.0 dBmV8Not LockedN/AUnknown0 Ksym/sec0 Hz0.0 dBmV

You need to get your line checked. You have errors in the line, power levels out of spec, and unlocked channels. All signs the isp needs to check the lines.

Thank you for your posts plemans . You were correct. A technician from Xfinity just came out and checked the line. He said the signals are all over the place. He fixed the line and now everything is working!

Osirus

Aspirant

Oct 08, 2020

CM700 Downstream Light blinking

Purchased a new CM700 and activated (via online) with Comcast. Before I had Arris SB6580 and had download speed of >150 mpbs, now I am getting <90 mpbs with blinking download stream light.

Here is a copy of the error logs. Can someone tell me how to fix this blinking downstream light and the errors seeing on the error log?

Thanks!

Oct 08 2020 02:53:54	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:54:11	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:54:23	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:54:26	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:54:26	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:54:41	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:54:53	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:54:56	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:54:56	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:55:14	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:55:27	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:55:30	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:55:30	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:55:46	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:55:59	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:56:02	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:56:02	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:56:19	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:56:35	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:56:38	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:56:38	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:56:54	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:57:16	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:57:19	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:57:19	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:57:34	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:57:47	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:57:50	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:57:50	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:58:07	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:58:29	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:58:32	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:58:32	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:58:49	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:59:05	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:59:08	Critical (3)	SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
Oct 08 2020 02:59:08	Error (4)	RCS Primary DS Failure
Oct 08 2020 02:59:25	Critical (3)	No Ranging Response received - T3 time-out
Oct 08 2020 02:59:41	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Oct 08 2020 02:59:44	Warning (5)	RCS Partial Service

13 Replies

plemans

Guru - Experienced User

Oct 08, 2020

Do you also have a screen snip of the cable connections page?

If you have any splitters, amplifiers, or attenuators in line, I'd remove them. These can sometimes cause issues.

Check the line for kinks, damage, cheap/bad connectors, loose connectors. Preferablly, move the modem to right where the coax enters the home to prevent wiring in the home from being the issue.

Osirus

Aspirant

Oct 08, 2020

I am not sure what you mean by a "screen snip of the cable connections page."

With regards to other devices, I do not have any splitters, amplifiers, or attenuators.

I will try to replace the coaxial cable and see if that helps.

Thanks for your suggestions.

Osirus

Aspirant

Oct 08, 2020

If you mean this...

Apply Cancel

Frequency start Value

This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.

Starting Frequency

<tabindex=-1>Startup Procedure</tabindex=-1>

Procedure	Status	Comment
Acquire Downstream Channel	663000000 Hz	Locked
Connectivity State	Ok	Operational
Boot State	Ok	Operational
Security	Enabled	BPI+
IP Provisioning Mode	Honor MDD	honorMdd(4)

Downstream Bonded Channels (Partial Service)

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	UnCorrectables
1	Locked	QAM 256	26	555000000 Hz	-17.3 dBmV	30.0 dB	22769409	5169734
2	Locked	QAM 256	27	561000000 Hz	-10.7 dBmV	33.4 dB	5312	2128
3	Locked	QAM 256	28	567000000 Hz	-8.5 dBmV	35.0 dB	18	0
4	Locked	QAM 256	29	573000000 Hz	-7.7 dBmV	30.5 dB	26287	0
5	Locked	QAM 256	30	579000000 Hz	-7.5 dBmV	31.6 dB	3541	0
6	Locked	QAM 256	31	585000000 Hz	-7.0 dBmV	27.8 dB	53227437	4307073
7	Locked	QAM 256	32	591000000 Hz	-7.2 dBmV	31.9 dB	35	1
8	Locked	QAM 256	33	597000000 Hz	-7.0 dBmV	33.0 dB	32	0
9	Locked	QAM 256	34	603000000 Hz	-6.4 dBmV	33.4 dB	11	0
10	Locked	QAM 256	35	609000000 Hz	-6.4 dBmV	34.9 dB	6	1
11	Locked	QAM 256	36	615000000 Hz	-6.4 dBmV	34.9 dB	30	0
12	Locked	QAM 256	37	621000000 Hz	-5.7 dBmV	34.9 dB	8	0
13	Locked	QAM 256	38	627000000 Hz	-6.0 dBmV	35.0 dB	21	0
14	Locked	QAM 256	39	633000000 Hz	-5.7 dBmV	35.1 dB	6	0
15	Locked	QAM 256	40	639000000 Hz	-6.2 dBmV	34.9 dB	3	0
16	Locked	QAM 256	41	645000000 Hz	-6.0 dBmV	34.9 dB	5	0
17	Locked	QAM 256	42	651000000 Hz	-6.2 dBmV	34.5 dB	35	0
18	Locked	QAM 256	43	657000000 Hz	-6.2 dBmV	34.9 dB	0	0
19	Locked	QAM 256	44	663000000 Hz	-6.4 dBmV	34.4 dB	2	0
20	Locked	QAM 256	45	669000000 Hz	-6.2 dBmV	34.8 dB	2	0
21	Locked	QAM 256	46	675000000 Hz	-6.2 dBmV	34.8 dB	6	0
22	Locked	QAM 256	47	681000000 Hz	-5.7 dBmV	34.8 dB	11	0
23	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
24	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
25	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
26	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
27	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
28	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
29	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
30	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
31	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0
32	Not Locked	N/A	N/A	0 Hz	0.0 dBmV	0.0 dB	0	0

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	1	5120 Ksym/sec	16400000 Hz	43.5 dBmV
2	Locked	ATDMA	2	5120 Ksym/sec	22800000 Hz	44.3 dBmV
3	Locked	ATDMA	3	5120 Ksym/sec	29200000 Hz	44.8 dBmV
4	Locked	ATDMA	4	5120 Ksym/sec	35600000 Hz	45.0 dBmV
5	Locked	ATDMA	5	1280 Ksym/sec	39600000 Hz	42.3 dBmV
6	Not Locked	N/A	Unknown	0 Ksym/sec	0 Hz	0.0 dBmV
7	Not Locked	N/A	Unknown	0 Ksym/sec	0 Hz	0.0 dBmV
8	Not Locked	N/A	Unknown	0 Ksym/sec	0 Hz	0.0 dBmV

Forum Discussion

CM700 Downstream Light blinking