Visitor
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3 Messages
MB8611 restarting several times per day
I saw some posts indicating there have been issues with the MB8611 in recent years, and was wondering if that was ever resolved, or if I just need to buy a new modem.
If anyone can share some insight, it would be appreciated.
Modem is on software version 8611-19.2.18.
Looking at the Internet Troubleshooting Tips post, and comparing against the modem connection info:
- Downstream power level is within the min/max values, except for one OFDM PLC channel (34)
- Downstream SNR exceeds the minimum 35dB, except for one OFDM PLC channel (34)
- Upstream power level is lower than the min value
- Upstream SNR is not shown
- 3 T3 timeouts in event log within the past 90 minutes
- We already had an Xfinity-initiated tech visit previously and all unnecessary splitters/amps have been disconnected
- We're paying for 1.3 Gbps, but Xfinity speed test consistently shows ~600-700 Mbps. However, I don't actually remember ever achieving real gigabit speeds on any speed test in the past...
XfinityBillie
Official Employee
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3.9K Messages
23 days ago
@user_01bfcd Thank you for taking the time to reach out to us here on our Xfinity Forums. You mentioned you have had a technician out, how long ago was that? I appreciate the troubleshooting details you have shared and attempted, can you tell me how you are running that speed test? Is it via a Wi-Fi connection or hardline to the modem with an Ethernet cord. Are you using a stand-alone router as well?
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EG
Expert
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116.3K Messages
23 days ago
The two downstream OFDM channels are borked. There is a cable tilt issue at the highest frequencies. As far as OFDM channel 34 goes, we've seen this here before, where Comcast places an OFDM channel too high in the frequency range near the end of the plant's bandwidth capability. Some of their cable plants and equipment still only extend out to 850 or 1000 MHz operation. At 957 MHz, it may be too close to the roll-off point of the plant's bandwidth capability, which explains the weak power level and SNR value.
You'll need to get the techs involved again to investigate, but this may need to be escalated to their engineering department for correction. Good luck with it.
(edited)
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