Phone Line Quality Checks
1. There should be a single good quality (not old, tangled, torn) phone cord of not more than 6ft in length going from the 'line' phone port on the modem to a phone jack. It should not go through any other phone devices such as an answering machine, fax machine or cordless phone. There should be no splitter used on the phone jack. One can usually plug a telephone into the "phone" port on the modem, but for troubleshooting it should be removed, especially if it is a very cheap phone.
2. For troubleshooting, temporarily unplug every other telephone device in the house. A large number of devices, or a faulty device can degrade the phone line quality. If it then works, you can then add back in devices one at a time until you have located the offending device.
3. Sometimes an old phone jack will not make good contact, if possible try plugging the computer into a different jack. Also, if the phone jack is old or in a humid environment the copper contacts in the jack may be corroded. You can try to clean them using a standard pencil eraser.
4. Line noise - pick up a phone, push '1' to make the dial tone go away and listen. It should be silent. Buzzing, popping or other noises could indicate a problem.
5. Is the problem linked to weather conditions? If you have more connection troubles during very wet weather it could indicate moisture getting into your telephone terminal box on the side of the house, or into the cable to your house through faulty insulation.
6. Newer telephone terminal boxes have a strandard telephone jack in them into which the whole house plugs in. If you have this then you can unplug the house, plug in a good phone and listen for noise. This will help determine if the problem is inside or outside the house.
7. If all else fails, try your computer at another location such as a friends
house or our office. If everything works great at a new location, then the
phone line at your house is suspect.