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Contributor
hsostock
Posts: 6
Registered: ‎04-12-2012

Re: At a loss....

I have the same modem and I am also experiencing this same issue. It seems to occur only when doing activities that use a lot of upstream/downstream, such as skype video or online gaming, in which case it will happen every 5-15 minutes. When my connection drops, the modem will flash all lights, then only the power led is on, and it performs the reconnection routine.

 

My signal stats:

 

Downstream:
Power Level:              Signal to Noise Ratio:
Channel 1: -7.7 dBmV    39.0 dB
Channel 2: -7.2 dBmV    40.1 dB
Channel 3: -6.8 dBmV    39.0 dB
Channel 4: -6.7 dBmV    39.8 dB
Channel 5: -7.0 dBmV    39.5 dB
Channel 6: -6.8 dBmV    39.6 dB
Channel 7: -7.2 dBmV    39.2 dB
Channel 8: -8.1 dBmV    39.2 dB

Upstream:
Power Level:
Channel 1: 49.5 dBmV
Channel 2: 49.5 dBmV
Channel 3: 0.0 dBmV
Channel 4: 0.0 dBmV

Cable Expert
i-am-nerdburg
Posts: 11,230
Registered: ‎06-27-2009

Re: At a loss....

Your power levels are OK, but would be out of spec if they change just a little bit. You'll want to try and grab signal levels as soon as you can after your next loss of connection for comparison. It would probably be beneficial for you to improve the signal to your modem. You would do this by keeping the cable run as short as possible and minimizing the number of splitters before the modem.

Regular Contributor
evil_hero
Posts: 57
Registered: ‎10-29-2011

Re: At a loss....

[ Edited ]

yep exact thing i have noticed, things will work for the most part, as soon as my wife starts skype, it bombs. Last night I played some games on the pc, it bombed, BUT I played some games on the PS3, it was fine... I dont get it, but I'm getting extremely sick of this.

 

However I dont think it is the modem, I had the Moto sbg6580 before, and had the same issue. Also a friend here at work has the same modem dpc3008 (he is the one that recommended it) he lives maybe 10 miles away from me, and has no issues at all. Although I know he doesnt play games, he does use netflix, and he has never complained about a drop.

Contributor
hsostock
Posts: 6
Registered: ‎04-12-2012

Re: At a loss....

Happened again just now while playing an online game, was unable to grab signal levels while the connection was down, but immediately after it came back up I grabbed the following:

 

Downstream
Power Level Signal to Noise Ratio
Channel 1    -7.4    39.2
Channel 2    -7.0    40.2
Channel 3    -6.6    39.1
Channel 4    -6.5    39.8
Channel 5    -6.7    39.8
Channel 6    -6.6    39.4
Channel 7    -6.9    39.4
Channel 8    -7.9    39.5


Upstream
Power Level:
Channel 1 49.5
Channel 2 49.5
Channel 3 0.0
Channel 4 0.0

 

I am in an apartment building, so I can't be sure what the connection is like outside my apartment, but I have a single coax coming into the apartment and going to a splitter. My cable modem is the only device connected to it through the splitter, although there are 3 other outlets; I have tried connecting through the other outlets to see if maybe it was an issue with the cable, but it did not make a difference.

Regular Contributor
evil_hero
Posts: 57
Registered: ‎10-29-2011

Re: At a loss....

hsostock, 

were you JUST gaming? or did any one of your machines, (phones included) have skype running?

 

Cable Expert
i-am-nerdburg
Posts: 11,230
Registered: ‎06-27-2009

Re: At a loss....

[ Edited ]

hsostock

There aren't any red flags. You may have some noise issues that we can't see. It's probably time for a tech visit.

Cable Expert
i-am-nerdburg
Posts: 11,230
Registered: ‎06-27-2009

Re: At a loss....

Huumm I see there are at least three of you having the same issues and you all have the same modem. Humm...

Regular Contributor
evil_hero
Posts: 57
Registered: ‎10-29-2011

Re: At a loss....

I was having disconnects before this modem. I had similar issues with the moto sbg6580. 

 

Connection Expert
EG
Posts: 43,264
Registered: ‎12-24-2003

Re: At a loss....

[ Edited ]

 

I would say that the upstream power at 49.5 dB is a potential issue. That is borderline out of spec and it may be fluctuating even higher out of spec intermittently.

 

Are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured ? If there aren't any uneeded 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 putting them back together again, then perhaps it's best to book a tech visit to investigate and correct.

Connection Expert
EG
Posts: 43,264
Registered: ‎12-24-2003
Contributor
hsostock
Posts: 6
Registered: ‎04-12-2012

Re: At a loss....

Anything that uses heavy bandwidth has caused it. So, online gaming, skype, downloading/uploading large files, all have individually caused the drop.

Contributor
hsostock
Posts: 6
Registered: ‎04-12-2012

Re: At a loss....

EG, if i connect my cable modem directly to the line coming from outside and bypass the splitter, I get the following signal levels:

 

Downstream Channels
Power Level: Signal to Noise Ratio:
Channel 1: 5.0 dBmV 40.6 dB
Channel 2: 4.8 dBmV 41.0 dB
Channel 3: 5.5 dBmV 40.5 dB
Channel 4: 5.7 dBmV 41.0 dB
Channel 5: 5.4 dBmV 40.8 dB
Channel 6: 5.5 dBmV 40.7 dB
Channel 7: 5.2 dBmV 40.5 dB
Channel 8: 4.5 dBmV 40.6 dB

Upstream Channels
Power Level:
Channel 1: 39.0 dBmV
Channel 2: 39.0 dBmV
Channel 3: 0.0 dBmV
Channel 4: 0.0 dBmV

 

These numbers (I'm guessing) are a lot better, so I'm going to run with this for awhile to see if it's better. I'm guessing there may be a bad cable or splitter.

Connection Expert
EG
Posts: 43,264
Registered: ‎12-24-2003

Re: At a loss....

[ Edited ]

There is much more "wiggle room" now. Let us know how things turn out.

Contributor
hsostock
Posts: 6
Registered: ‎04-12-2012

Re: At a loss....

No luck. Even after eliminating the splitter I am still experiencing dropped connections at about the same rate when doing high-bandwidth activities. As far as I can tell, it only occurs during periods of heavy uploading, e.g. Skype and online games will cause an issue, but something like Netflix or Spotify that is mostly downloading do not seem to cause any drops.

 

I checked signal levels after a drop, and they still look about the same.

Regular Contributor
Posts: 73
Registered: ‎12-28-2006

Re: At a loss....

Call comcast and ask them what you Upstream SNR is. It should be 30dB or more.