Troubleshooting
•The MTA1 28ST/NT or power supply may be defective. If you have another
Caution: Do not under any circumstances replace the power supply module with one designed for another product, as it may damage the MTA1 28ST/NT and void your warranty.
The MTA128ST/NT does not respond to commands
•Make sure the MTA1 28ST/NT is plugged in and turned on. (See None of the LEDs Light When the MTA 128S T/NT Is On.)
•Try resetting your MTA128ST/NT by turning it off and on.
•Make sure you are issuing the MTA128ST/NT commands from the data communications software, either automatically, or manually in terminal mode. (You cannot send commands to the MTA1 28ST/NT from the DOS prompt.)
•Make sure you are in terminal mode in your data communications program. Then type AT and press ENTER. If you get an OK response, your connections are good and the problem likely is in your phonebook entry or session settings.
•If you don’t get an OK, the problem may still be in the communications software. Make sure you have done whatever is necessary in your software to make a port connection. Not all communications pro- grams connect automatically to the COM port. Some connect when the software loads and remain connected until the program ends. Others, like MultiExpress Terminal, can disconnect without ending the program (make sure the Connect icon looks plugged in). MultiExpress Terminal also allows multiple terminals to be open, but only one can access the MTA128ST/NT at a time. If MultiExpress Terminal reports that it cannot make a connection, yet the MTA128ST/NT’s TR indicator is on, click on the Window menu to see if more than one terminal is open. The MTA128ST/NT’s TR indicator shows that the software has made a connection with the TA through the COM port.open, but only one can access the MTA128ST/NT at a time. If MultiExpress Terminal reports that it cannot make a connection, yet the MTA128ST/NT’s TR indicator is on, click on the Window menu to see if more than one terminal is open. The MTA128ST/NT’s TR indicator shows that the software has made a connection with the TA through the COM port.
•Your communications software settings may not match the physical port the MTA128ST/NT is connected
to. The serial cable may be plugged into the wrong
•If the MTA1 28ST/NT is on, the cable is plugged into the correct port, the communications software is configured correctly, and you still don’t get an OK, the fault may 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, check the cable description on the packaging to
make sure the cable is correct for your computer.
•Peripheral expansion cards, such as bus mouse and sound cards, may include a serial port preconfig- ured 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 communications port. Be sure to disable any unused ports.
To look for address or IRQ conflicts, select File, Run in Program Manager, type MSD, and press ENTER. Then select Mouse, COM Ports, and IRQ Status and note the addresses and IRQs that are in use. If you find an IRQ conflict, note which IRQs are not being used, then change one of the conflicting devices to use one of the unused IRQs. If you find an address conflict, change the address of one of the conflicting devices.
To change a port address or IRQ,
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