Modem Troubleshooting- Solve common problem/ issues with modems

Though we intend to write this article for dial up modem, this also equally applies to other sort of modems- internal or external, FAX or VOICE or DATA modems, DIAL UP or DSL modems. Please, verify your problem with the modem to troubleshoot it. For the reference purpose, we are talking about Motorola’s SM56 internal modem.
If there is a problem when using the SM56 modem, and your communications application does not explain the problem, check the following list of symptoms and tips.

• My Communications Software Cannot Use the Modem at COM 5

Some communications applications, such as older versions of AOL, do not communicate with a COM port higher than COM4. Sometimes on Windows 98SE platforms the SM56 install program will not be able to map the modem to a COM port number below COM5.

• There is no dial tone

1.   Ensure that the telephone cable is securely connected at both ends.
2.   Ensure the telephone cable is plugged into the correct jack on the modem — some modems provide a second jack for handset support.
3.   Unplug the telephone line cable from the computer, and connect it directly to a telephone from the wall outlet. Check for a dial tone. If there is none, the problem is in the telephone line or system. Call the service provider.

• Get An Error Message “Telephone signal not detected, please check connection “

1.   Ensure that the telephone cable is securely connected at both ends.
2.   Ensure the telephone cable is plugged into the correct jack on the modem — some modems provide a second jack for handset support.
3.   Unplug the telephone line cable from the computer, and connect it directly to a telephone from the wall outlet. Check for a dial tone. If there is none, the problem is in the telephone line or system. Call the service provider.

• Get An Error Message “Loop current too high, please close the application and check the telephone line connection”

When you try to dial a connection an error message box pops up, indicating that you are not connected to a proper analog phone line. This is the SM56 digital line guard feature, which protects against hardware damage if the modem is plugged into a high current phone outlet — such as a digital phone jack. The modem automatically detects the over-current and goes back on-hook before hardware damage occurs. Check the phone outlet and make sure that it is a real analog phone line. Try another analog phone jack.

• I Cannot Hear Call Progress

1.   Ensure that your speakers are connected to the speaker output jack on your sound system.
2.   Call progress reporting on the SM56 requires Microsoft DirectX 5.0 (for Win 98SE, WinMe and Win2K) or later be installed on your PC, and that your sound system/drivers support Microsoft DirectX playback.

• The modem cannot complete a connection to another modem

1.   Ensure that your modem is dialing the correct number. Ensure that you’ve specified the correct area code, if one is required.
2.   Determine whether the remote modem is correctly configured to communicate with yours.

• The modem does not answer incoming calls

1.   Ensure that the automatic answer parameter is set to one of the enabled options, using the ATS0 command (ATS0=1 to answer after one ring, ATS0=2 to answer after two rings, and so on).
2.   Ensure that no other devices, such as fax or answering machines, are answering calls before the modem does.

• The modem disconnects during a connection

1.   Ensure that the telephone cable is securely connected at both ends.
2.   Another phone extension in the house might have been picked up.

• Data is not transmitted or received for unusually long periods of time

1.   Re-dial the call.  (The telephone line connection may be poor).
2.   Try another ISP number, the server could be busy.

• Streaming applications like RealPlayer stop receiving data and report “Net Congestion”

This usually occurs when the ISP, Internet, or streaming host side server is busy and there are many users competing for bandwidth. It is not a modem problem.

• You cannot enter tone selections successfully when calling tone-driven applications

When dialing a remote system that requires you to enter selections using the telephone keys, such as a voice-mail depot or bank-account information provider, you can lengthen the duration of the tones your modem sends, so that the remote system can detect them better.  To adjust the DTMF tone length, use the command AT+VTDn (where n specifies the tone duration).

• The modem does not respond to AT commands

1.   Ensure that your communications software is configured to use the same COM port as the modem’s COM port.
2.   Reset modem parameters to default options by entering AT&F; then re-enter custom options.

• The modem responds to commands, but they do not appear on the screen

Usually this is because the local echo is turn OFF. Turn it on by issuing ATE1 and hit <Enter>.

• You’ve installed a new peripheral device; now the modem does not work

1.   In the Windows desktop tray, select Start.
2.   Select Help. The Windows Help Topics window appears.
3.   Select the Contents tab.
4.   Select If You Have a Hardware Conflict.
5.   A series of troubleshooting actions appears.  Follow the appropriate sequence.

• The modem connects; then meaningless characters appear

This is usually caused by Error correction turned off. To correct:
In Win98/ME:
1.   Open the Control Panel. Double click the Modems icon.
2.   Click on the COM port that the Motorola SM56…Modem is installed on
3.   Click on Properties.
4.   Select Connection.
5.   Click on Advanced.
6.   Check the Use Error Control-Required to Connect box.
In Win2K/XP/Vista:
1.   Open the Control Panel. Double click the “Phone and Modem Options” icon.
2.   Click on the Modems Tab
3.   Click on the Motorola SM56…Modem
4.   Click on Properties.
5.   Click on Advanced.
6.   Click on Change Default Preferences
7.   Select “Standard EC” from “Data Protocol” drop down menu.

• The modem cannot connect; the Error Control option is selected

The modem may be connecting at a rate higher than appropriate for the line conditions.
1.   Use the AT%B command to limit the maximum connection rate.
2.   Lower the rate, using AT commands, until the problem is corrected. You can add AT commands to do this; refer to the next section.

• How Do I Add AT Commands Before the Modem Dials My ISP?

1.   Open the Control Panel.
2.   Double-click the “Phone and Modem Options” icon.
3.   Click on once to select the Motorola SM56…Modem.
4.   Click on Properties.
5.   Select Connection.
6.   Click on Advanced.
7.   In the Extra Settings box, chain AT commands as needed. You do not need to enter the AT prefix, but it will not hurt if you do.