by Philo Farnsworth

Created on: January 21, 2009

If being on-line is mission critical for your work or play, it can be very aggravating or even costly to be off-line. Diagnosing modem problems can be a daunting task if you don't know where to start. Here are some simple tips to get you back on line fast.

The solution to most modem issues is to simply unplug the modem, leave it off for at least ten seconds, then plug it back in. This is called "power cycling" and it forces the modem to check itself for errors. It will also force the modem to establish a fresh connections. You may also want to shut your computer down and restart it as well. If you have an internal dial-up modem, that's about all you can do other than check that your phone service is working and you have it plugged in correctly.

If you have a cable or DSL modem you should first check the lights on the modem. Lights differ, but generally all the lights should be lit and one light should be flashing (usually labeled "link" or "data".) If some or all of the lights are not working, you should check that your modem is physically set up correctly and that all cables are seated properly. You can also turn your television on to verify that the cable service is working. If you have DSL, check for dial tone and that DSL filters are installed on each phone outlet.

If you have a router, bypass the router and connect the modem directly to your computer. If you are able to connect, the problem is with the router. Leave the router out of the loop for now, even if you still can't connect.

There are a couple of simple things you can check with just a few keystrokes. First, make sure your network adapter is enabled. You can usually view your available adapters from the control panels in Windows based systems. If you have a wireless adapter, be sure it is disabled. Then briefly disable your firewall and try to connect. If you can connect with the firewall off, you have a software issue.

If you still can't connect, it's time to take a closer look at the modem. You can see your modem's diagnostic screen right from your web browser. Generally, you should type 192.168.100.1 or 192.168.1.1 directly into your web browser's address bar. You can often find the proper address to access the diagnostic screen printed on the modem itself. What you'll find on the diagnostic screen varies greatly by manufacture. Often if something is not working properly, the diagnostics page will display some type of warning. For cable modems, power levels are displayed. As a general rule of thumb, your downstream levels should be -10 dBmV to +10 dBmV and the upstream power should be 40 dBmV to 50 dBmV. If your levels are outside of these specification, you should double check your cable wire for damage or loose connectors.

If you are using a Windows based machine you can open the scary looking command prompt. Click on Start>Run type in "cmd". A black window will open. Type "ipconfig/release". The type "ipconfig/renew". This forces the computer to get new network information from the modem. Tip: if you are using Windows Vista, the "Run" command is not in the start menu by default anymore. You can get it by right clicking on Start>Properties>Customize.

Even though you may dread it, if at this point you are still not connected, you should call your internet provider for help. They can often remotely diagnose your problem or send help between 8am and 5pm three weeks from next Tuesday.

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