Line Noise Troubleshooting - chasms.com

Line noise can have many sources. Here are some things to try to diagnose or solve the problem:

• 1. Unplug answering machines, other phones from your phone lines and see if you still get the garbage characters when you dial up. Some devices can put a small drain on the phone line current and interfere with your modem transmission.
• 2. Unplug both ends of the phone cable (from the modem and the wall) and plug it back in. If your modem is external, do the same for the cable connecting the modem to your computer.
• 3. Wiggle the phone cable while you're dialed up and see if the garbage characters appear. If they do, you might need a new cable. They're pretty cheap, and you can find replacements at most discount department or electronics stores.
• 4. You can also clean off the gold contacts on the jacks and plugs with a contact enhancer such as Stabilant-22 (designed for stereo products.) Make sure the computer is unplugged when you do this.
• 5. When talking on the phone, listen carefully for line noise. If you hear static of any sort, your local telephone lines or the phone lines in your house may be at fault. Call your local telephone company and request investigation or repair.
• 6. If the source of the problem is the phone lines in your house, you may be billed for the service call.
• 7. Be sure you've got the right settings in your modem program (ProComm, Telix, Zterm, etc), like the proper baud rate for your modem, 8 data bits, no parity, 1 stop bit.
• 8. If all else fails, you can go to a lower baud rate, or buy one of the error-correcting modems available on the market now. Some can even handle people picking up the phone in the middle of a call.

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More on line noise.

PROBLEM:

     Line noise

SOLUTION:

      A TTY window not only is a great tool for getting troubled modems connected, but after they get connected, check and see if you see any garbled text. If so, this is the explanation for the random disconnects.
      You may want to recommend that they purchase an inexpensive line noise suppressor from Radio Shack or a local electronics store. The adapter is called RJ31X Line Noise Suppressor, which costs $3-$4. In most situations it very affective in rectifying to random disconnects. If the line noise still persist, then you know to have them contact their local phone company to run a digital check on the line. Also, home security system, flourecent lights w/ ballasts, stereo systems, and any kind of splitters, A/B selector switches are possible causes of line noise that may be an easy fix.

     If a modem disconnects and you have tried everything, set up a TTY window and look for line noise. It will save you and your customer a lot pain and frustration. Thanks to Rob Lewis.

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