Atari Modem Fix
Atari's XM301 modem is an excellent buy for the money. However, there is a serious problem with the wiring that everyone should be aware of. Of the 13 wires coming from the serial input/output cable, only nine wires are actually used by the modem. The remaining four wires do nothing. Inside the modem, these four wires have approximately ⅛-inch of bare wiring exposed with no insulation. If they short out, they can damage one or more pieces of equipment daisy-chained in your computer system. This problem has been widespread in the Albany area, and it has been discovered in other areas as well.
To fix the problem, begin by unplugging the modem from your computer (this disconnects the power). Remove the two screws from the bottom of the modem and snap apart the plastic case. Carefully locate and cut off the four unconnected wires, making sure that the pieces don't fall inside the modem and that you don't cut any other wires. Cover each of the wires with electrical tape if you can, or at least make sure the wires don't touch each other and are covered with a single piece of tape. Then reassemble the modem and enjoy it safely.
Before receiving your letter, we had read about this potential problem in an Atari user-group newsletter and immediately checked an XM301 modem to see if it was true. The four bare wires were easy to find, and the fix took less than five minutes. Although our particular modem has been used for more than a year with no trouble, it's not hard to envision how the bare wires could cause a short-circuit under the right conditions. Thanks for the tip. However, since your suggestion does involve opening the modem case and cutting wires, we must remind readers that they perform this modification at their own risk. Opening the case may void the warranty, and cutting the wrong wire could make the modem nonfunctional. Anyone who has any doubts should refer the job to someone with more technical experience.