bugzod
Premium
join:2008-05-08
Beaver, PA
| [Connectivity] Intermittent loss of connection with SBG900
1) Your location: Beaver, PA
2) A description of the problem.
Approximately one month ago, my modem seems to reboot randomly, causing my internet to disconnect for roughly 1-5 minutes. The outages vary in duration and occur at any time of the day, regardless of peak usage time. I had initially lost all connection during a pretty heavy rainstorm. I changed out a splitter in the garage and it seemed to fix the problem. Less than one week later, the intermittent connectivity problems began. I had had no significant problems with my SBG900 and Comcast service for about four years.
Here's what I tried initially:
* Hard reset the modem.
* Checked the signal status for the modem info. All normal. See below.
* Replaced splitter in garage last week. Seemed to work for a while then started random sync loss again. Replaced splitter again with current, big honkin’
Monster 2gb, no change. (I was later told by a comcast tech it would not work coz it was gold.)
* Changed splitter in outside cable box. Worked well for about 20 mins then problem returned. Put original splitter back in box.
* Hooked the modem up to each of the lines coming into the garage. Both exhibited same loss of sync problems experienced upstairs at computer.
* Turned off the wireless broacasting on the modem. Also unplugged both wireless adapters on my Tivos and a 2.4 GH baby monitor. No change.
* Called Comcast support. They noted the random loss of sync during our conversation and scheduled the service call. They told me there had been no firmware upgrades for my modem pushed recently.
* First Comcast tech found no problems with the signal. Put a new splitter on.
* Picked up a new leased RCA DCM425. Upon calling Comcast to program it, it would not work. Had worse symptoms than the Moto. About an hour later, it was working like a charm.
* Figured it must really be the Modem that went south, ordered a new SBG900 from Buy.com
* Received the new SBG900. Upon installation, same problem. Scheduled new Comcast tech visit with HSI guys, not just a basic tech like last time.
* Two CHSI techs found no signal degradation or packet loss. They could not give me a reason for why all of a sudden, my old Modem stopped working with their service and a brand new one didn't either. They told me there was nothing else they can do on their end and essentially told me to pound salt because even though their service no longer worked with a compatible modem, there was nothing they could or would do.
3) Is the issue intermittent, constant or does it occur at a specific time of day?
It is intermittent. It doesn't matter what time of day or night.
4) Your modem make, model & firmware version.
SURFboard SBG900 Combo cable modem and wireless gateway
Software version: SBG900-2.1.15.0-SCM00-NOSH
Hardware version: 3
5) Describe any home networking if applicable. (i.e. routers, hubs, adapters, etc.)
Unsplit line from box plugs directly into modem/gateway.
CAT-5 cable to Desktop
Two Tivo Wireless G adapters. Tivos cannot connect regularly because of intermittent problem, when non-connecting, gives error message that it cannot get an IP assigned by DHCP.
6) List any firewall and/or anti-virus software you have installed. Include what version you have.
Norton Internet Security v.8.0.7.1 (Firewall enabled)
Norton Anti-Virus v.11.0.17.1
Windows Firewall disabled
7) MODEM SIGNAL LEVELS: (Pasted 05/10/2008)
Downstream
Value
Frequency
591000000 Hz Locked
Signal to Noise Ratio
37.3 dB
Power Level
8.2 dBmV
Upstream
Value
Channel ID
3
Frequency
20000000 Hz Ranged
Power Level
40.0 dBmV
8) LOG ENTRIES (Night of May 10th but the same with my first SBG900):
2008-05-10 22:01:16--3-Critical--R004.00--Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2008-05-10 22:00:47--3-Critical--T005.00--SYNC Timing Synchronization failure - Loss of Sync
2008-05-10 21:48:47--3-Critical--T004.00--SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
These are repeated ad nauseum
Everything passed when I did Line packet loss testing.
The only other factors that coincidentally occurred at same time problems started:
* Heavy rainstorms
* Tivo software udpates
* extensive Microsoft update
Other than that, I'm just plain stumped. I now own what I believe to be two perfectly good SBG900s that will no longer work. My brand new one cannot be returned to Buy.com because of their ridiculous 14-day from shipped BS return policy. I haven't reattached the RCA modem yet so I can run tests but will have to do so soon. Sorry if this post is so verbose...
Thank you so much in advance for any help you can provide. |
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Joedub
join:2005-10-30 | The downstream signal looks a little high for the transmit that you show. Did comcast install this or did you pick up a self install kit? Is it off the first splitter? how far off the street are you? Is there and amp in your basement? |
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bugzod
Premium
join:2008-05-08
Beaver, PA
| Comcast installed with a separate drop about 10 years ago.
The line from what I can tell is unsplit from the box.
I am about 60 ft from the street.
There is no amp in the basement.
*Update* I spoke to tech support again last night and he noted my sync history looked like an EKG instead of a flat line over the last week. He emailed his technical supervisor, scheduled another service call and promised me some relief. We'll see.
I'm still thinking bad amp on pole because we have had some consistent rainy weather and the outages have seemed to increase. |
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Joedub
join:2005-10-30 | reply to bugzod
If it was a bad Amp more than you would be complaining it would be the whole street. I would say your either have bad ingress or you have bad BER probably a combination of both. |
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carwashguy
@cox.net | reply to bugzod
I'm having the same issue
I need help also |
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bugzod
Premium
join:2008-05-08
Beaver, PA
| Is it also with the sbg900?
I thought I found the source of the problem. The modem was plugged into an Ultra power surge protector that seemed to have problems with being overloaded. I thought that maybe the modem was very sensitive to slight drops in current and that was what was making it reboot. If the power dropped, it would be like doing a hard reset.
However, after plugging it into different outlets throughout the house, it still lost sync and rebooted like normal. It just didn't seem to do it as often.
After my THIRD tech call to my house, Comcast has pretty much washed its hands of me. The Moto people may exchange my newer modem under warranty, but it will have to be cleared as a special circumstance.
I know this is Comcast's problem. If only they would figure it out. I've been back to using the leased RCA modem with no drops with extensive use. |
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