
5 Troubleshooting
To change a port address or IRQ in Windows 3.1x,
Windows 9x and 2000:
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 may be defective. If you have another
The Modem Dials But Cannot Connect
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.
You can narrow the list of possibilities by using extended result codes. Extended result codes are enabled by default. If they have been disabled, include V1X4 in the modem’s initialization string, or in terminal mode enter ATV1X4 and press ENTER. When you dial again, the modem reports the call’s progress.
If the modem reports NO DIALTONE, check that the modem’s phone line cable is connected to both the modem’s LINE jack (not the PHONE jack) and the phone wall jack. If the cable looks secure, try replacing it. If that doesn’t work, the problem might be in your building’s phone installation. To test the building
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