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Trouble-shooting lost Internet Access - a step-by-step guide

Almost every business now depends on internet access to some degree or other. It can be both time-consuming and frustrating to resolve issues of slow speed or lost access.

This guide will help you work through the various possibilities for lost internet connection, with reference to broadband connection over fixed telephone line.

There are a number of reasons why internet access may be lost, and the only way to resolve it is by process of elimination through the various elements.

Key components in a broadband internet setup

  • Internet service provider (ISP)
  • Telephone line
  • ADSL filter (microfilter) – a small adaptor plugged into your phone socket
  • Broadband router or modem
  • Internal network - cabled or wireless
  • Your computer

Summary of possible causes

  • Phone line fault (external)
  • Phone line fault (internal)
  • Broadband microfilter missing or faulty
  • Router needs a reboot, or faulty
  • Router lost configuration settings, ISP login
  • Internet Service Provider (ISP) issue
  • Internal network or wiring fault – computer not connected to router
  • Internal wireless network fault
  • Computer issue – configuration, corruption, virus attack

Broadband Trouble-shooting steps

  1. Consider first of all whether anything has changed since the system last worked. For example, changes to the phone system, changes to the broadband router, equipment moved, new software installed on the computer, connecting wires disturbed.
  2. Check all physical connections – power to the router, phone line connection from the microfilter to the router, network connection between computer and router.
  3. Restart your broadband router (usually by disconnecting the power). Ensure that it has started correctly by checking the status lights. Restart your computer.
  4. Are the router indicator lights normal? Apart from a power light, most routers have lights that show Broadband (ADSL), Internet (WAN) and internal network (LAN) status. Consult the documentation for your router if you are unsure as to whether a light should be steady, flashing etc for normal operation. Generally speaking, an ADSL (Broadband) light means that a basic broadband signal is present. An Internet light often flashes to indicate that the router is logged on to the ISP and there is activity.
  5. If you have more than one computer on the network, can any of the other computers connect to the internet? If so, the issue is with the computer. (If you have only one computer, if you can borrow another one and connect it to your system, this will show quickly whether the problem is with your broadband service or your computer.)
  6. Check the telephone line by using a handset to make a call. If the line is provided by BT you can also do a “Quiet Line Test” by dialling 17070 and following the instructions. As the name implies, you should be able to make a completely silent connection. Any noise indicates a faulty line which should be reported to your phone service provider.
  7. If your broadband is connected to an extension phone socket, locate the Master phone socket. This is the one that is directly connected to the phone wires coming in from outside. It will be 85mm wide and have a BT logo on it (a British Telecom “T”, BT logo, or OpenReach logo, depending on age).
  8. Plug your broadband filter and (hence router) directly into the Master socket, and unplug all other telephone equipment that may be connected to the same line, including any at extension sockets. Try the broadband connection again.
  9. If the problem persists, unscrew the two screws on the face of the master phone socket, remove the faceplate, and plug the broadband router and filter into the test socket you will find underneath. Test internet access again.
  10. Restart your broadband router (usually by disconnecting the power). Ensure that it has started correctly by checking the status lights.
  11. If the router status lights do not show an internet connection, call your ISP Help Desk. You may also be able to log on to the router and view its connection status and diagnostics pages. It is possible that the router has lost its settings. The instructions for dealing with this vary by router model, but it may for example be possible to reset the router to factory state by pressing a button on it, and then re-run the setup CD provided by your ISP.
  12. Try replacing the ADSL (broadband) microfilter. If you have phone extension sockets on the phone line that you use for broadband, every socket should have an ADSL microfilter on it. Filters can deteriorate over time, and may need replacement.
  13. If your computer connects wirelessly to the router, try moving one or the other so that they are close enough to connect with a network cable. If internet access now works, the problem is with the wireless connectivity.
  14. If the router appears to be running normally and is apparently connected to the internet, restart your computer and try internet access again. Use more than one website as a test to see if it is working. If you have more than one internet browser installed, eg Internet Explorer, Firefox, Chrome, then try using a different browser.
  15. If the computer will still not browse the internet, look at the icons in the system tray on the bottom right of the screen. In most cases, a Windows computer will show some indication there if there is a network problem. Some versions of Windows may offer to diagnose connection failures.


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