Having trouble with my Cable Modem

ruggutah · Post by **ruggutah** » Wed Mar 28, 2007 11:53 am

I am new to this forum and I've tried reading other posts but I hope someone may be able to help me. I have a Motorola SB5100 Surfboard Cable Modem. Been having intermittent trouble for about a year now where I'm online and for about 1 minute everything stops and I cant connect online and then after the minute is up the lights on my modem all go out except power and receive and then receive flashes once and stays lit and then send is flashing for a little while and stays lit and then online is flashing for a little while and stays lit and then I'm ok. When the trouble occurs it comes in spurts and happens about 5-10 times in a row and then stops for a long time maybe until the next day. Had the cable company out a couple times(Western Broadband) said everything seemed ok and replaced the modem. Here's what it does when it goes down:
2007-03-28 15:33:25 3-Critical 0x040D9A2C DHCP WARNING - Non-critical field invalid in response.
2007-03-28 15:33:14 3-Critical 0x04E33948 No Ranging Response received - T3 time-out
2007-03-28 15:33:01 3-Critical 0x04E33A10 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2007-03-28 15:32:28 3-Critical 0x04E33A74 Started Unicast Maintenance Ranging - No Response received - T3 time-out

Here's the signal strengths when normal:

Downstream Value
Frequency 117000000 Hz Locked
Signal to Noise Ratio 36 dB
Power Level -2 dB The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

Upstream Value
Channel ID 17
Frequency 26000000 Hz Ranged
Power Level 44 dBmV

Here's my signal levels when it is actively crashing:

Downstream Value
Frequency 117000000 Hz Locked
Signal to Noise Ratio 36 dB
Power Level -6 dB The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

Upstream Value
Channel ID 17
Frequency 26000000 Hz In Progress

Power Level 33 dBmV

Any help would be greatly appreciated.

YARDofSTUF · Post by **YARDofSTUF** » Wed Mar 28, 2007 5:42 pm

Upstream power level of 33 seems kinda low.

ruggutah · Post by **ruggutah** » Wed Mar 28, 2007 10:34 pm

Went to Radio Shack and bought one of those gold plated splitters. The guys that work there said they knew of the trouble and that this should fix it. We'll see!

ruggutah · Post by **ruggutah** » Fri Mar 30, 2007 12:26 pm

OK, put the radio shack splitter on it and thought I was OK but it did it again just now! But this time when I took a snapshot of the power levels I noticed that the Upstream Power Level was around 52 dBmV usually I am around the lower 40's. Still looking for any kind of help from somebody. Thanks

ace · Post by **ace** » Fri Mar 30, 2007 1:06 pm

First off get rid of that cheesy "gold plated" splitter. The only thing passing the signal is the copper wire inside the cable itself. Next thing is to call and have a trouble call setup with your cable company. If your upstream is fluctuating like that it needs to be fixed.

chpalmer · Post by **chpalmer** » Sun Apr 01, 2007 2:06 pm

The upstream power level is the power level your modem is transmitting.

The headend at the cable co. will adjust this as needed to "hear your modem" at the same level as everyone else on your node. (Cellular phone companies do this also with your phone.) In the case of your modem they want to hear it at 0dBmV at the node receiver on their end.

While the modem is syncing up this number will change. Generally the modem has stored previous information and refers back to it at restart.

During ranging the modem syncs with the other modems on the system. Everyone has to transmit at the correct time to keep from "talking" at the same time and confusing the headend. If this doesnt happen correctly, restarts can happen. Ingress on the cable system can also cause restarts. Its really up to the techs to detect these issues and solve them, if this is whats happening.

Low modem upstream numbers are not bad. It means your modem is not having to transmit as much to be heard. Drastic changes with signal strength over any time period, upstream or downstream, are bad however and should be diagnosed.

You might try a hard reset on your cable modem and see if it helps. Look for the little hole on the back and hold it for 30 seconds after power up, Then let it reboot. It should take a few minutes.

Good Luck

Oh yea- and put your old splitter back.

http://www.usr.com/support/6000/6000-ug/two.html

ruggutah · Post by **ruggutah** » Sat Apr 07, 2007 10:20 am

Thanks a lot! I guess I really got hosed on that splitter!

cableguy2k7 · Post by **cableguy2k7** » Sun Jul 27, 2008 2:26 am

yea ruggutah umm you dropline from your utility pole comign to your house can be bad the cable guy replaces that free that dont cost anything i know time warner dont charge becuz of that cable is realy old over 5 years old it can be the cause but it can also be the modem itself you can buy modems or lease them from the cable company

cableguy2k7 · Post by **cableguy2k7** » Sun Jul 27, 2008 2:29 am

you only use splitter for multiple connections such as multiple modems/cableboxes not one you want your cable coming direct to your modem