Fax/Modem Troubleshooting Tips

Fax/Modem Troubleshooting Tips

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The following general-purpose advises are provided as a free service to our customers and visitors. Actual procedure may vary among brands. Read your product user manual carefully before any work. Directron.com is not responsible for any damage as a result of following any of these advises. You are welcome to distribute these tips free to your friends and associates as long as it's not for commercial purposes.

My modem is a 56K, but I can connect to the Internet only at slower speed.
The current copper wired telephone lines are limited only to about 53K. If you are connected only to 33.6 or 28.8K, check the following first:

• Is your modem compatible with the modem used at your ISP?
• Is your modem set up to run at full speed?
• What's the maximum speed your ISP allows?
• How far away are you from your ISP?
• Some modems need special initiation strings to get full speed.
• Some conditions are out of your control, such as weather and conditions of the telephone lines in your community.
• Problems may occur when you are dialing through a phone system such as one in a hotel.

Modem answers incoming calls and then returns to the on-hook condition, disconnecting the caller:
This occurs most often when connecting to a UNIX system. In most case, the host does not prefer to see any result or command echo codes. If this is the case, the codes can be disabled by adding E0 Q1 to the modem configuration string.

The modem dials and appears to complete the connection, but the communications software does not enter the correct mode. (The screen remains blank)
This is normally caused by an I/O address or IRQ conflict. Verify that the COM port is not in use by any other serial device and if necessary use another COM port or I/O address settting. Refer to your computer manual on how to determine what serial ports are installed.

The modem dials and appears to complete the connection, but the communications software does not enter the correct mode. (The screen remains blank)

• There may be an I/O conflict (see the solution for the previous problem).
• The Result Codes may have been disabled by the software configuration set up. Check if Q1 is in the configuration or initialization string. If so, change it to Q0.
• Your software may require numeric result codes rather than verbal result codes. Use either V0 for numeric result codes or V1 for verbal result codes in your initiazation or configuration string.
• Some software require full extended result codes (i.e., CONNECT 33600 instead of CONNECT). This can be controlled by the Xn command. X0 sends a summarized code (CONNECT) and X4 sends a full extended code (CONNECT 33600)

The modem does not auto answer
The auto answer mode is determined by the S0 register. If S0 has been set to 0, the modem will not answer. Asign another value to S0 by entering the following command: S0=n, where n = the number of rings to occur before the call is answered (ATS0=2, the modem answers after two rings)

The modem always answers the phone.
Set the S0 register to 0. ATS0=0.

The communications software displays, "No Dialtone."
Make sure that your phone cable is working properly and that it is firmly seated to the phone socket at your phone jack and in the real panel of the modem.

A high pitched squeal is emitted from the external speakers
This phenomenon is "feedback" and occurs when the microphone is pointed at the external speaker or is close enough to pick up the speaker output. This may be remedied by using a unidirectional microphone, making sure that it is pointed away and as far from the speaker as functionally possible. Another option is to use a headset with an attached microphone.