Error 680: There is no dial tone
Check the phone connection to the modem. Make sure your phone cable is securely plugged into your wall jack. Make sure the other end of the cable is securely plugged into your modem. 99% of modems have two phone jacks on them--one is a line-in and one is a line-out. You need to make sure you're plugged into the correct port. The correct port is usually labeled LINE or TELCO, or has a picture of a phone jack next to it. The other port is usually labeled PHONE or has a picture of a telephone next to it. Make sure your cable is plugged into the LINE port. If you are unable to see the labels on the ports (they can be very difficult to identify unless under direct lighting), just move the phone cable from one port to the other and try again.
Make sure the jack you're plugged into does in fact have a dialtone. Unplug the phone cable from the back of the modem and plug it into a phone. Pick up the phone and see if you hear a dialtone. If you do, but your modem does not, then there is possibly a problem with your modem or its settings (continue to the following steps).
Make sure the correct modem is specified in your Dial-up Networking connection. As with Error 602 and Error 633, sometimes when a modem is changed in the computer the old modem is not removed and the dial-up networking connection updated and told to connect using the new modem--Windows can't tell the modem to pick up and dial if it's trying to talk to the wrong modem! Follow these steps to make sure the modem you're using is the correct one.
- Windows 95/98/Me: Double-click on My Computer, then double-click on Dial-Up Networking (Me users will click on Start, go to Settings and select Dial-Up Networking). Right-click on your connection icon and select Properties. The modem your computer will try to use to establish this connection will be listed at the bottom of the window under Connect using. Feel free to click on the down arrow next to the modem to see if there is any other modem listed. If there is, select that modem and try your connection again.
- Windows 2000: Click on Start, go to Settings and select Network and Dial-up Connections. Right-click on your connection icon and select Properties. The modem your computer will try to use is listed at the top under Connect using.
- Windows XP: How you do this will depend on how your computer is set up, but most users will click on Start and click on Control Panel. If you are asked to Pick a Category, click on Network and Internet Connections, then click on Network Connections. Other users will just locate Network Connections in the list and double-click it. Once in the Network Connections, right-click on your connection icon and select Properties. The modem your computer will try to use is listed at the top under Connect using.
Make sure Windows can communicate with your modem at the basic level. Once you know which modem your computer is trying to use for the connection, you will go into your modems settings in Windows to ensure that modem does in fact exist and Windows can communicate with it. Click on your version of Windows for instructions on how to do this:
Contact your computer support technician. If all else fails (or if this just seems like too much for you to take on yourself), you should contact whomever would support your computer. It could be that the modem has physically failed and needs to be replaced.