How to Diagnose Telephone Modem Problems

In spite of inroads made by cable and DSL, telephone modems are still the most popular way to connect to the Internet, and they're an essential element of every road warrior's portable computer. Sometimes, though, they just refuse to make the connection. The following tips apply to both Windows and Mac computers (except steps 9 and 10, which are for Windows users only).

Difficulty:

Moderate

Instructions

1. Check your cable connections. If you have an external modem, check the serial cable between the computer and the modem. For both internal and external modems, check the phone cord connection.

2. Make sure the modem is turned on and has power. If you have an internal modem, you can try removing it and reseating it.

3. Check the phone line to make sure there's a dial tone. This is also a good time to make sure that a phone on the same line wasn't accidentally left off the hook. If your modem is on a dedicated phone line, connect a phone temporarily to check the line.

4. If the modem is dialing but failing to connect, double-check that the phone number entered in your Internet connection program is correct.

5. If you're using a notebook or laptop computer, make sure you don't still have a phone number entered for dialing out of a hotel or from a different area code.

6. Use a telephone to dial the access number or fax number that you're attempting to connect to, then listen to make sure there's a data signal at the other end.

7. Re-enter your password for the service you're trying to connect to. Passwords can accidentally get changed at the user end.

8. If you're dialing an Internet service provider (ISP), contact it to make sure it isn't experiencing system problems that are preventing you from connecting.

9. Test your modem in Windows by using the Modems control panel. Go to Start, Control Panel, Modems, then select the Diagnostics tab. Select the serial (COM) port your modem is installed on and click on More Info. Windows will perform diagnostic tests and show you a window that lists the commands that were sent to the modem and the responses.

10. If you recently upgraded your Windows system software and your modem stops working or returns an error message, visit Microsoft's Product Support Services pages (http://search.support.microsoft.com) to see if there are specific compatibility issues with your modem. Search on "modem troubleshooting."

Tips & Warnings

• If your modem shares a phone line with a phone that has call-waiting, incoming calls might disrupt the modem connection. To get around this, you can temporarily disable call-waiting by adding *70 to the modem command string. You can do this easily in Windows via the Modems control panel's Dialing Properties settings.