When it comes to diagnosing the modem and any other computer problem, always start with the most obvious first. Modem problems may be repaired as fast as re-booting the computer or can be as complex as resolving hardware conflicts.
First remember to check for the most obvious signs of trouble, such as loose connections at the rear of the computer for external modems.
Internal modems may have their retaining screw at the expansion slot loose or missing. Phone line connections may simply be inserted in the wrong connector. Nearly all internal modems are inserted into the PCI or Peripheral Component Interconnect slot in the system unit.
No Power At the Modem
For Internal Modems, first try inserting the modem in a different PCI Slot. Reboot the computer and click on Start, Control Panel, and click the Phone and Modems icon.
Then click on modems, properties, and look for the statement "This Device Is Working Properly". You can click on Diagnostics and run a test to see if the modem has power as well.
External modems can be checked for power by inspecting the adapter plug to see if it is plugged in completely. Look to see if any indicator lights are flashing and be certain you are using the adapter for your modem.
Be sure the surge protector or wall outlet is providing power by plugging in a lamp or a radio. If the radio works, the culprit may be the adapter or the external modem itself.
If you purchased the modem in your town, you may have the chance to return it to the store and ask the technician to test it with a known good power adapter. You can been replace either the adapter or modem.
Modem Disconnects Often
If your modem, whether internal or external, is working but disconnects from the Internet often, without warning, check to be sure your call waiting option is not enabled.
Another culprit that cause this headache is line noise. This noise and interference can be caused by such things as loose wiring. Poor waterproofing, old wiring, worn phone jacks are other causes of line noise. Make sure no other equipment is using the same line that your modem is on.
Be sure other devices as your fax machine, answering machines or even security alarms are not sharing the same line as your modem.
Other PCI devices may be causing conflicts with your modem. Clicking the Control Panel, and clicking the modem icon will show the message "This Device Has A Problem" or something similar if there is a conflict.
Windows will offer ways to resolve the conflict. Take the time to carefully follow instructions to correct any conflicts that may be present.
Loose Data Lines for Internal modems and loose or damaged connectors for External modems can cause data lost as well. Visual check and double check these connections.