For first time installations, you want to make sure that you are installing your modem on or after your service activation date. However, most DSL orders may have sync several days before the due date. No sync means you have no dsl signal or the dsl signal is too weak to maintain a connection with your modem.

The modem currently being shipped for new customer self-installations is the Motorola 2210.
On the 2210,4100 and the 5100b modem, no sync is indicated by the DSL light flashing red.

When there is sync the DSL light will flash green it may also briefly flash red before it goes solid green indicating the the modem has sync and is trained.

If the 2210, 4100 or 5100b modem is configured for "PPP is on the modem" the Internet light will flash green while it's authenticating the username and password, once authenticated the Internet light will go solid green.
Also the Internet light will flash red if authentication fails on either end.
If the 2210, 4100 or 5100b modem is configured for "PPP is on the computer" or "Bridged mode (PPPoE is not used)" the Internet light will remain unlit.

1) Verify with AT&T HSI that the correct phone number was set up for DSL. If you have more than one phone line in the home, it is not uncommon for the wrong line to be provisioned with DSL.

2) Check your connections. Be sure to plug the modem into the line you ordered DSL on, it will not work on other phone lines. Plug the DSL modem straight into the wall jack with no filter.
Make sure all phones, analog modems, fax machines, and any other devices that use the DSL/phone line is plugged into a filter before it's plugged into a phone jack. Occasionally, you could get a bad filter. If you can get sync without the 2 port filter but lose sync with the 2 port filter on the modem line, then your 2 port filter is bad. If you have only one jack in the room and need to use the 2 port filter, try another. Any device attached to a phone jack needs a filter.
The DSL modem does not need a filter.

3) Be sure to use the data cable/phone cord that came with the modem. Sometimes, the regular flat phone cord will work fine for your DSL modem and sometimes it won't. These cords can get damaged easily and could work for dial-up and not for DSL. Someone can use a 100 ft flat phone cord and sync up just fine. Others can have a 5 ft cord they have used for years that won't allow DSL to sync up.
If you plan on using a cord other than the data cable/phone cord that came with the modem....Don't, you should consider purchasing a longer CAT-5 patch cord with RJ-45 jacks at both ends from a computer store or Radio Shack to replace the short yellow CAT-5 patch cord.

4) Verify that you do not have anything such as a home security alarm, doorbell, water meter, or other devices on the DSL line that could interfere with sync. If you do, you will need a pots splitter to filter all the house wiring and install a dedicated cable connected before the pots splitter and jack for the DSL modem.

5) If all the above checks out fine, then you may have a line problem, there is one more step you can take to isolate the problem to your house wiring or to AT&T HSI's wiring. Take the modem to the NID and connect the modem to the test jack on the customer side of the NID.
NOTE: When you disconnect the RJ11 jack at the NID you'll be disconnecting all house phones.
If the modem can sync at the NID test jack that shows a problem with the house phone wiring.
If the modem cannot sync at the NID test jack that shows a problem with AT&T HSI's part of the wiring.


Graphic by Riss_Centaur


got feedback? got feedback?

Any feedback you provide is sent to the owner of this FAQ for possible incorporation and shown publically as well.

by wayjac
last modified: 2008-01-23 15:34:35