Chapter 6 - 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 may 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 may be installed behind a company phone system (PBX) with an internal dial tone that sounds different from the normal dial tone. In that case, the modem may not recognize the dial tone and may treat it as an error. Check with your in-house telephone switch (PBX) personnel or the PBX system manual to see if you can change the internal dial tone. If you can’t, change your modem’s initialization string to include X3, which makes the modem ignore dial tones.

•If the modem reports BUSY, the other number may be busy. Try again later. BUSY also may indicate that 9 was not added to the phone number (if required to dial 9 for an outside line). If you are required to dial 9 to get an outside line, the easiest way to dial it automatically using legacy software is to include it in the modem’s dial prefix, e.g., ATDT9, (the comma inserts a pause before the number is dialed). If you have set up your connection through Dial-Up Networking or another communications program, find the dialing configuration dialog box that allows you to add a dial prefix. Enter 9 as the prefix when dialing.

For example, in Windows 95/98, select Start Settings Control Panel, and then Modems. In the Modems Properties sheet, select the appropriate modem model (e.g., Multi-Tech MT5634ZPX), click Dialing Properties and type 9 in the local and long distance boxes in the How I dial from this location box.

•If the modem reports NO ANSWER, the other system has failed to answer, or you may have dialed a wrong number. Check the number.

•If the modem reports NO CARRIER, the phone was answered at the other end, but no modem connection was made. You may have dialed an incorrect number and a person answered instead of a computer. A NO CARRIER message may also indicate the modem you are calling is turned off or the software on the receiving end is faulty or incorrectly configured. Check the number and try again or try calling another system to make sure your modem is working. You may also try calling the modem’s phone number from your telephone. If you hear harsh sounds, a modem is answering the call. If the modem is answering, the modems may be having problems negotiating due to modem incompatibilities or line noise. Try the call again connecting at a lower speed by setting register S37 to a lower rate (e.g., by typing ATS37=11 in the terminal window and pressing Enter).

The modem disconnects while online

•If you have call waiting on the same phone line as your modem, it may interrupt your connection when someone tries to call you. If you have call waiting, disable it before each call. In most telephone areas in North America, you can disable call waiting by preceding the telephone number with *70 (check with your local telephone company). You can disable call waiting automatically by including the disabling code in the modem’s dial prefix (e.g., ATDT*70,—note the comma, which inserts a pause before the telephone number is dialed). For example, in Windows 95/98 software, select Start Settings Control Panel, and then Modems. In the Modems Properties sheet, select Multi-Tech MT5634ZPX, click Dialing Properties. Check This location has call waiting and select the correct code for your phone service.

Note: *70 is used only in the United States.

•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 for the modem only.

Multi-Tech Systems, Inc. MT5634ZPX User Guide

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