Troubleshooting Broadband Cable Modem Problems
By Stephen Bucaro
If you've been accessing the Internet through a broadband cable modem but now you can't
connect, this guide provides some troubleshooting tips.
Check Your Modem's Front Panel LEDs
The LED's on the front of your modem provide information about it's functioning. The Power
and Cable LEDs should be on. The PC LED should be blinking. This "PC Activity" light
indicates that the PC and the Modem are "shaking hands" indicating they are ready to talk to each
other. If it's off or on solid, there is a bad connection or software configuration problem.
The Send LED should be blinking when your PC is sending data packets to the Internet. The
Receive LED should be blinking when your PC is receiving data packets to the Internet. If they're
off, it means your PC is not sending or receiving data. If they're on solid, it means you have
a software or hardware problem.
Check All Connections
Make sure the power cord is securely plugged into the modem and into the wall outlet.
Check that the coaxial cable is connected securely to the back of the modem and to the wall
faceplate (don't over-tighten). Check that the Ethernet cable is securely connected to the
modem and to the computer.
Power Cycle Your Modem and Router
If you are using a router, remove power from the router and the modem. Wait ten seconds
and then power the modem back on, then power the router back on. Give them both time to
reboot. Then try connecting to the Internet again with your computer.
Reboot your Computer
Shut down your computer, wait ten seconds and then restart. After your computer reboots
try connecting to the Internet.
Remove your Router from the Configuration
If you still cannot connect the Internet, eliminate the router from the setup. Connect your
computer's Ethernet port directly to the modem's Ethernet port with one of the network cables.
Once you've done this, you'll have to power cycle the modem and reboot the computer.
After the modem and computer reboot try connecting to the Internet again.
Examine Your IP Address
In the Start button Search text box type cmd.exe and press the [Enter] key.
This will open a DOS command prompt. At the command prompt type ipconfig. This
should return information about your TCP/IP connection. Examine this information to make
sure your Ethernet adapter has a local IP address, subnet mask, and default gateway
address. To close the command prompt type exit and press the [Enter] key.
To renew your PC's IP address, open a command prompt, and type in ipconfig with the
release option (ipconfig /release [Enter]), then with the renew option
(ipconfig /renew [Enter]). Close the command prompt by typing exit and pressing the [Enter]
key. Try connecting to the Internet again.