Cable modems can experience myriad technical malfunctions that can manifest themselves as any number of issues on your home Internet connection. Intermittent connectivity, slow Internet speeds, and inability to connect at all are some of the most common problems associated with cable modems. While each of these problems requires different troubleshooting procedures, a few general steps can address these and many other problems a cable modem may experience.
Reset the cable modem by removing its power cord for 30 seconds and plugging it back in. This can clear network timeouts and other common errors that appear on a cable modem that has been running continuously.
Remove the coaxial cable by unscrewing it from the modem's coaxial connection. Wipe down the coaxial connection on the back of the modem with a soft, dry cloth to clear any static electricity buildup. Also check the copper needle in the middle of the coaxial cable for any bending or or other damage. Reconnect the coaxial cable, screwing on the metal connector until it is just hand-tight.
Replace the modem's ethernet cable with a different one to test the modem's ethernet port. It is common for ethernet cables to simply go out, but if you experience continual problems with multiple ethernet cables, there may be a problem with the port.