My modem lights are not lighting up [Closed]

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19674
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Wednesday October 8, 2008
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Hello,i have windows xp and my modem is not lighting up.my modem is a motorola surfboard model sb5120.
when I plug it in the power is on but the receive button keeps flashing and it wont connect online.
also my ethernet cord is connected and the pc activity button lights up,and the network also connects
but no internet connection. if someone can help it would be good

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19674
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Wednesday October 8, 2008
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You probably have a weak signal from the cable. Call your cable operator and have them run a diagnostic. I just went through this with Comcast. You might have a problem in the house wires of in the signal strength from the street.

Good Luck
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Try to power off the modem and your computer. Wait for 1 minute before you power on the modem. Then wait for the modem lights to become stable before you turn on the computer. If you still don't have a connection to the Internet, better contact your Internet provider so they can troubleshoot your problem.
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19674
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Wednesday October 8, 2008
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June 15, 2019
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I had Comcast (local cable internet supplier) service my exterior line today.
The serviceman used my browser to display the Motorola modem readings at the end of my house line.
Enter 192.168.100.1 in your browser address line and hit enter
then click on Signal on the left side.

The Downstream Power Level is the most important reading (just remember that -4.0 is better than -10.0). You might still be able to use the internet with a -13 reading but it should be above -10.

SNR (signal to noise ratio) is also important it should be above 33dB.


Readings outside this working range can be caused by a poor signal from the cable supplier or from bad connections (too many splitters) or too long a cable run in your house. Each splitter cuts your Power Level in half. 50 feet of marginal quality or poor connection on the cable might drop the signal by 4 dBmV.

Motorola Surfboard SB5120 QAM 256 (Working range)
Down Power (between -10 and +10 dBmV)
SNR (higher than 33dB)
Up Power (between 30 and 55dBmV)