DSL Troubleshooting Information & Guide
This guide will lead you through the steps in getting your DSL working again when you are unable to connect to the Internet. Please make sure that you're familiar with your DSL equipment by reviewing our How DSL Works and DSL Hardware pages.
Power-cycle the DSL modemTurning the modem off and back on causes it to re-synchronize the DSL signal and the network connection to your computer. Often, this by itself is enough to fix a DSL connection problem. To do this, unplug the power cord from the DSL modem, wait about 30 seconds, then plug it back in. If you are using an external router or switch, power-cycle it as well.
Check the DSL "Sync" lightThe 'Sync' light on the modem (may also be labeled "SYNC/PPPoE" , "DSL", "WAN") should be lit solid, not blinking. This light will flash when the modem is trying to connect to your DSL service. It should take about 30 seconds for your DSL modem to connect and display a solid light. If the DSL Sync light continues to flash, try the
- With the exception of your DSL modem, ensure that all devices plugged into the phone line, including fax machines, satellite receivers, and alarm systems, have a DSL line filter on them. These filters prevent interference with your DSL signal. The DSL modem should be the only unfiltered device on the DSL phone line.
- Verify that there is a clean dial-tone on the phone line that is plugged into your DSL modem. You will need a regular analog telephone to do this test. If there is lack of dial-tone then the line will need to be checked by a technician.
- The phone cord coming from your DSL modem should plug directly into the wall outlet. Try bypassing any splitters or other devices as they can sometimes cause interference with your DSL signal. We suggest you remove and re-plug the phone cable into the DSL modem and the wall jack to ensure the cable is plugged in securely. The cable should 'click' when it is inserted securely. If the modem works bypassing the filter then the filter should be replaced.
- Try moving the DSL modem along with its power supply and phone cable to a different telephone wall jack. There may be internal wiring issues causing problems with a specific wall jack or group of wall jacks at your location.
- Assuming you are using line-sharing DSL (meaning that your phone and DSL share a line) turn off the DSL modem and listen for audible noise on the line. If you hear snaps or static when making a phone call, it is likely that the phone company will need to repair your wiring before DSL will work reliably.
- As a final test, running your DSL modem directly into the "NID" (usually a grey telephone box on the outside of your home where the wires attach from the telephone pole) eliminates the possibility of inside wiring issues.
Reboot the computerIt seems trivial, but you should always begin troubleshooting computer problems by rebooting your computer! This is particularly important if your computer has worked fine in the past and only just began to exhibit problems. Sometimes Windows Updates cause weird issues that can be solved by a restart.
Are you using a router?Many people install a router to enable multiple computer to connect to the same DSL line, or to allow wireless network access. If you are not able to connect to the Internet, the problem may be in the router and not the DSL line. Try connecting one computer directly to the DSL modem using an ethernet cable. If your DSL service includes a static IP address, then you will need to change the TCP/IP settings on your computer to connect directly to the DSL modem.
Verify your TCP/IP settingsIf you have recently changed how your home network is setup (for example, by adding a router) or if your DSL is newly installed, check that the TCP/IP settings
(your IP Address, Subnet Mask, Gateway, and DNS) are correct and match those provided in your installation documents. Most computers should have the "Automatically get IP/DNS Settings" radio field check so that the settings are assigned by the router itself.
- Remove any extra network devices
If possible, remove any network devices (such as hubs, wireless routers, or network switches) that sit between your computer and the DSL modem. By running your computer directly into the DSL modem, you can eliminate the possibility that the router or other device on your network is causing the problem.
- Check the
lights on the modem
Check the status of the various LED lights located on the front panel of the modem. The “POWER” light should be lit solid. (On some modems, this light is on the power supply itself.) If the power light is off or flashing, check that the power supply is plugged securely into the modem, and plugged into a working wall outlet.
Check the "LAN" light
light (labeled "LAN" or "ETHERNET") should be lit solid
or blinking rapidly. The LAN link light will blink when
your computer is sending or receiving data. If the link
light is not lit, try the following:
1. Make sure the Ethernet cable connecting your DSL modem with your computer is plugged securely into the back of the DSL modem. We suggest you remove and re-plug the cable into the DSL modem and your computer to ensure the cable is plugged in securely. The cable should ‘click’ when it is pushed into place.
2. If you have not done so already, try bypassing the router and running a cable from your computer directly into the DSL modem. This will help you eliminate the possibility that one of these devices may be causing your problem.
3. The cable that connects your DSL modem with your computer may be bad. Try a different cable if possible.