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Intermittent connection issues with SB6121

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Intermittent connection issues with SB6121

A few months ago my modem started losing connection at random times.  I have to unplug the power, and sometimes the coax connections to restore connectivity.  Now it happens around 3-6 times a day.  My modem, SB6121, looks to be on the EOF list, but the way it was described is that EOF just means that it is not supported or provided by Xfinity.  The interruptions in service don't seem to make much sense, if EOF doesn't mean that the modem will simply not work anymore. 


Do I HAVE to buy a new modem if i am using SB6121?  I am attaching an image of the modem statisctics as well.  


Any help would be greatly appreciated.  

Diamond Problem Solver

Re: Intermittent connection issues with SB6121

The upstream power is borderline / on the high end and it may be intermittently fluctuating even higher out of spec. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.