Chapter 7 - Troubleshooting
If the modem reports NO DIALTONE, check that the modem’s telephone line cable is connected to both the modem’s LINE jack (not the PHONE jack) and the telephone wall jack. If the cable looks secure, try replacing it. If that doesn’t work, the problem might be in your building’s telephone installation. To test the building installation, plug a telephone into your modem’s telephone wall jack and listen for a dial tone. If you hear a dial tone, your modem might be installed behind a corporate phone system (PBX) with an internal dial tone that sounds different from the normal dial tone. In that case, the modem might not recognize the dial tone and might treat it as an error. Check your PBX manual to see if you can change the internal dial tone. If you can’t, change your modem’s initialization string to replace X4 with X3, which will cause the modem to ignore dial tones.
If the modem reports BUSY, the other number might be busy, in which case you should try again later. However, it might indicate that you have failed to add a 9, the prefix to the phone number if you must dial 9 for an outside line.
If you must dial 9 to get an outside line, the easiest way to dial it automatically is to include it in the modem’s dial prefix; e.g., ATDT9. Note the comma, which inserts a pause before the number is dialed. By inserting 9, into the dial prefix, you do not have to include it in each directory entry.
To change the dial prefix in Windows HyperTerminal, select Connect from the Call menu, click Dialing Properties, and type 9 in the local and long distance boxes in How I dial from this location.
If the modem reports NO ANSWER, the other system has failed to go
If the modem reports NO CARRIER, the phone was answered at the other end, but no connection was made. You might have dialed a wrong number, and a person answered instead of a computer, or you might have dialed the correct number but the other computer or software was turned off or faulty. Check the number and try again, or try calling another system to make sure your modem is working. Also, try calling the number on your telephone. If you hear harsh sounds, then another modem is answering the call, and the modems might be having problems negotiating because of modem incompatibilities or line noise. Try connecting at a lower speed.
Poor line conditions can affect the connection. When using V.34 or V.32
The Modem Disconnects While Online
If you are not using Modem on Hold, Call Waiting can interrupt your connection when someone tries to call you. If you have Call Waiting service, disable it before each call. In most telephone areas in North America, you can disable Call Waiting by preceding the telephone number with *70 (but first check with your local telephone company).
You can automatically disable Call Waiting by including the disabling code in the modem’s dial prefix (e.g., ATDT*70, – note the comma, which inserts a pause before the number is dialed). To change the dial prefix in Windows HyperTerminal, select Connect from the Call menu, click Dialing Properties, check This location has Call Waiting, and select the correct code for your phone service.
If you have extension phones on the same line as your modem, you or someone else can interrupt the connection by picking up another phone. If this is a frequent problem, disconnect the extension phones before using the modem, or install another phone line especially for the modem.
Check for loose connections between the modem and the computer, the telephone jack, and AC power.
You might have had a poor connection because of line conditions or the problem might have originated on the other end of the line. Try again.
Your ISP might have hung up on you because of lack of activity on your part or because you exceeded your time limit for the day. Try again.
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