MB6811 modem intermitent connection

This MB6811 had been working fine for a few months, but is rebooting several times a day lately.

I'm considering getting a different brand modem. Anybody have any luck replacing this dog?

F/W version

8611-21.3.7

Connection

Startup Sequence
Startup Step	Status	Comment
Acquire Downstream Channel	543000000 Hz	Locked
Upstream Connection	OK	Operational
Boot State	OK	Operational
Configuration File	OK
Security	Enabled	BPI+

Event Log

Time	Priority	Description
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xxxx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xxxx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xxxx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xxxx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
15:15:41 Fri Dec 23 2022	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=xxxx;CMTS-MAC=xxxx;CM-QOS=1.1;CM-VER=3.1;

Connection

Startup Sequence
Startup Step	Status	Comment
Acquire Downstream Channel	543000000 Hz	Locked
Upstream Connection	OK	Operational
Boot State	OK	Operational
Configuration File	OK
Security	Enabled	BPI+

Connection Status
System Up Time	0 days 00h:04m:36s
Network Access	Allowed

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Freq. (MHz)	Pwr (dBmV)	SNR (dB)	Corrected	Uncorrected
1	Locked	QAM256	20	543.0	6.5	45.2	0	0
2	Locked	QAM256	1	423.0	5.0	44.6	0	0
3	Locked	QAM256	2	435.0	5.1	44.6	0	0
4	Locked	QAM256	3	441.0	5.1	44.7	0	0
5	Locked	QAM256	4	447.0	5.2	44.7	0	0
6	Locked	QAM256	5	453.0	5.3	44.8	0	0
7	Locked	QAM256	6	459.0	5.4	44.9	0	0
8	Locked	QAM256	7	465.0	5.5	44.9	0	0
9	Locked	QAM256	8	471.0	5.6	45.0	0	0
10	Locked	QAM256	9	477.0	5.8	45.1	0	0
11	Locked	QAM256	10	483.0	6.0	45.3	0	0
12	Locked	QAM256	11	489.0	6.2	45.2	0	0
13	Locked	QAM256	12	495.0	6.3	45.4	0	0
14	Locked	QAM256	13	501.0	6.2	45.4	0	0
15	Locked	QAM256	14	507.0	6.3	45.3	0	0
16	Locked	QAM256	15	513.0	6.2	45.4	0	0
17	Locked	QAM256	16	519.0	6.3	45.4	0	0
18	Locked	QAM256	17	525.0	6.4	45.5	0	0
19	Locked	QAM256	18	531.0	6.5	45.5	0	0
20	Locked	QAM256	19	537.0	6.4	45.3	0	0
21	Locked	QAM256	21	555.0	6.9	45.4	0	0
22	Locked	QAM256	22	561.0	7.1	45.7	0	0
23	Locked	QAM256	23	567.0	7.2	45.8	0	0
24	Locked	QAM256	24	573.0	7.1	45.6	0	0
25	Locked	QAM256	25	579.0	7.2	45.3	0	0
26	Locked	QAM256	26	585.0	7.4	45.6	0	0
27	Locked	QAM256	27	591.0	7.6	45.7	0	0
28	Locked	QAM256	28	597.0	7.7	45.9	0	0
29	Locked	QAM256	29	603.0	7.7	45.7	0	0
30	Locked	QAM256	30	609.0	7.7	45.8	0	0
31	Locked	QAM256	31	615.0	7.6	45.7	0	0
32	Locked	QAM256	32	621.0	7.6	45.6	0	0
33	Locked	OFDM PLC	193	702.0	7.4	45.6	37649	0

Upstream Bonded Channels

Channel	Lock Status	Channel Type	Channel ID	Symb. Rate (Ksym/sec)	Freq. (MHz)	Pwr (dBmV)
1	Locked	SC-QAM	1	5120	35.6	38.0
2	Locked	SC-QAM	2	5120	29.2	37.8
3	Locked	SC-QAM	3	5120	22.8	37.8
4	Locked	SC-QAM	4	5120	16.4	37.5

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Responses

Accepted Solution

U

user_372112

Visitor

•

5 Messages

2 years ago

This rental modem has been working for a week now, so I guess the MB8611 was the issue. I'll live with the rental fee for now.

4

0

pickman711

New Poster

•

8 Messages

@user_372112 I would peek into these forums every once in a while to see if the MB8611 issue is resolved. $180 a year in rental fees is enough to buy a modem every year.

2 years ago

G

GUS_GuyUsingSystem

Visitor

•

44 Messages

@pickman711 I am still keeping tabs of this issue even though I migrated to an Arris S33 @ $180 after my < 12 months old MB8611 acted up.

I have started a dialogue with Moto support & sent them my logs last week. Crossing my fingers there that something positive comes out before my 14 days return window closes on the S33.

Obvioulsy Xfinity is useless.

But no way am I giving up on the Moto when it has been bulletproof for many who owned longer than I have.

And Moto just didn't go dumb overnight with modems - that is one of their legacy core competencies.

2 years ago

0

pickman711

New Poster

•

8 Messages

I just ordered the same S33. Hopefully it is resolved soon so I can return it.

Waiting for a response from Motorola, they're probably bombarded with others with the same issue.

2 years ago

0

@user_372112 Thank you for reaching back out here in this thread to let us know that the Xfinity gateway has been working without issue since it was installed! I would recommend contacting Motorola directly if you have any additional questions or concerns regarding the functionality of the MB8611 specifically at this time.

I no longer work for Comcast.

2 years ago

0

U

user_482ff9

Visitor

•

2 Messages

2 years ago

I honestly don't think it's the equipment. I've had nothing but problems with my service for 1.5 yrs now. I provide my own modem and I started with an Arris SB8200. Starting having intermittent connection just like you described. I thought maybe it's my modem, so I went ahead and bought a Motorola MB8611. It was good for awhile, but now back to the intermittent connection literally everyday. I'm supposed to have speeds of up to 300Mbps, and I'm lucky that I get 80Mbps.

0

BruceW

Gold Problem Solver

•

26K Messages

2 years ago

... MB6811 ... rebooting several times a day ...

The signal stats you posted from the MB8611 all look good, but there are other stats that the modem does not report, and the event log indicates that the modem is having trouble communicating with Comcast. Network connection problems like this are often due to poor coax connections or damaged coax cable, usually in or near your home. Running the cable through a surge protector, a defective splitter, or too many splitters can cause signal problems as well. If there is an amplifier in the line make sure it's getting power.

If you want to troubleshoot this yourself, please see Internet Troubleshooting Tips. If you can't find the problem or you'd rather have Comcast take care of it, call them at the phone number on your bill or 1-800-Comcast, or use one of the options on https://www.xfinity.com/support/contact-us/. It's not likely they can fix the problem remotely. If not, insist they send a tech out to identify the cause and correct it.

If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit ($70-$100) unless you have their Service Protection Plan ( https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device or anything outside your home you shouldn't be charged.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

0

CCChristopher

Problem Solver

•

577 Messages

2 years ago

@user_372112 Hello and thank you for reaching out over our Xfinity Community Forum, and Merry Christmas. I am so sorry to hear about these service issues you have been experiencing, that would definitely be really frustrating. I would be more than happy to assist you in scheduling the next availble technician to come out and take a closer look, if needed, no problem at all. Anything we can do to help a valued member of our Xfinity family, especially around the holidays. To continue with scheduling a technician, could you please send our team a direct message with your full name and full address? Our team can most definitely take a further look at this issue.

To send a "Direct Message" to Xfinity Support:

Click "Sign In" if necessary

Click the "Direct Messaging" icon or https://forums.xfinity.com/direct-messaging

Click the "New message" (pencil and paper) icon

The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there

- As you are typing a drop-down list appears. Select "Xfinity Support" from that list

- An "Xfinity Support" graphic replaces the "To:" line

Type your message in the text area near the bottom of the window

Press Enter to send it

See https://comca.st/3KQF8q9 for an example.

0

U

user_372112

Visitor

•

5 Messages

2 years ago

I wrench tightened all coax connectors and replaced a 10 foot cable from modem to tv box/modem splitter. Up time is almost 4 days now. If it goes downhill again, I will pay for a Comcast technician to come over and look at it.

0

U

user_372112

Visitor

•

5 Messages

2 years ago

It's failing again intermittently after a few days.

0

U

user_372112

Visitor

•

5 Messages

2 years ago

Ordered and installed a comcast rental modem. It's a decrepit Cisco XB3, with a loose something rattling around in the enclosure. It works at 400Mbs, but $15 a month? We'll wait and see if this works any better over the next week or so.

0

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MB6811 modem intermitent connection

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Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

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