Multi-Tech Systems MT5634ZBAV.92, MT5634ZBA-VV.90, MT5634ZBAV.90 Modem Cannot Connect When Dialing

Chapter 7 - Troubleshooting

￿Try resetting your modem by turning it off and on. If you are using DOS or Windows 3.1 communication software, make sure the initialization string includes &F as the first command, to cancel any “leftover’ command that could affect the modem’s operation.

￿If you don’t get an OK, the problem may still be in the communication software. Make sure you have done whatever is necessary in your software to make a port connection. Not all communication programs connect to the COM port automatically. Some connect when the software loads and remain connected until the program terminates. Others can disconnect without exiting the program. The modem’s TR indicator lights to show that the software has taken control of the modem through the COM port.

￿Your communication software settings may not match the physical port to which the modem is connected. The serial cable might be plugged into the wrong connector—check your computer docu- mentation to make sure. Or you might have selected a COM port in your software other than the one the modem is physically connected to—compare the settings in your software to the physical connection.

￿If the modem is on, the cable is plugged into the correct port, the communication software is configured correctly, and you still don’t get an OK, the fault might be in the serial cable. Make sure it is firmly connected at both ends.

￿Is this the first time you have used the cable? If so, it may not be wired correctly. Check the cable description on the packaging to make sure the cable is the right one for your computer.

￿Peripheral expansion cards, such as sound and game cards, might include a serial port preconfigured as COM1 or COM2. The extra serial port, or the card itself, may use the same COM port, memory address, or interrupt request (IRQ) as your communication port. Be sure to disable any unused ports.

Windows 9x: Right-click on My Computer, select Properties from the menu, click on the Device Manager tab, double-click on Ports, then double-click on the communication port your modem is connected to. In the port’s Properties sheet, click on the Resources tab to see the port’s input/output range and interrupt request. If another device is using the same address range or IRQ, it appears in the Conflicting Device List. Uncheck Use automatic settings to change the port’s settings so they do not conflict with the other device, or select the port the conflicting device is on and change it instead. If you need to open your computer to change switches or jumpers on the conflicting device, refer to the device’s documentation.

Windows NT 4.0: To look for address or IRQ conflicts, click Start, Programs, Administrative Tools (Common), and Windows NT Diagnostics. In the Windows NT Diagnostics dialog box, click the Resources tab to see which input/output ranges and interrupt requests are in use. If you need to open your computer to change switches or jumpers on the conflicting device, refer to the device’s documentation.

￿The serial port might be defective. If you have another serial port, install the modem on it, change the COM port setting in your software, and try again.

￿The modem might have a problem beyond the scope of this user guide. If you have another Multi- Tech modem, try the other modem (if there is no problem with the other modem, call Technical Support for assistance. See Appendix F for phone numbers).

The Modem Cannot Connect When Dialing

There can be several reasons the modem fails to make a connection. Possibilities include

￿lack of a physical connection to the telephone line.

￿a wrong dial tone.

￿a busy signal.

￿a wrong number.

￿no modem at the other end.

￿a faulty modem, computer, or software at the other end.

￿incompatibility between modems

￿poor line conditions.

Multi-Tech Systems, Inc. MT5634ZBA-Series User Guide 26