2400 BPS Internal Faxmodem (250-3509)  Troubleshooting  Faxback Doc. # 4887

When you have problems transmitting data with your modem (garbled data, 
intermittent errors, and so on), check to see that:

* The phone connection is clean and noise-free.
* No one is talking on the telephone line.
* The phone and all extensions are on the hook.
* The operation speed is correct for the modem you are using and the modem .
  with which you are communicating.

If you still cannot transmit data, disconnect your modem to see if the phone 
line is operating correctly. If it is, the trouble is probably in your modem. 
Take it to your local Radio Shack store for further testing and/or repair.

Also, the telephone company can change its lines and/or equipment. If these 
changes affect your modem or its connection, the phone company notifies you 
in writing so that you can take steps to ensure uninterrupted service.

Diagnostics:

Your modem has built-in diagnostic capabilities. Test patterns for the analog 
loopback can be generated by either the modem or the computer. You use the 
test commands (&T) outlined in "Modem Test Commands" to perform these test. 
The modem does not respond to an incoming call while in the diagnostic mode.
For further information on the testing mode, refer to Faxback Doc. # 4877.

Lightning:

Your modem has protection circuits, which meet or exceed FCC requirements, 
to reduce the risk of damage from surges in telephone and power line currents. 
However, lightning striking near or on these lines can damage the modem. A
strong enough power surge can not only damage your modem, but may also
damage your computer because the modem is internally connected to your 
computer's circuits.

Lightning damage is uncommon. However, if this concerns you or if you live 
in an area with frequent and/or severe electrical storms, we suggest that 
you unplug your electronic equipment during the storms. Alternatively,
surge protectors exist for both power lines and modem lines.

(dtc-07/28/93)