Our page on General ADSL faults may be useful before proceeding here.

The first step in resolving any broadband issue is to power cycle the router or modem.  For a router this means taking power away then waiting for 10 seconds (to allow the capacitors to drain) then after reconnecting the power, waiting for 2 minutes to see if the problem is automatically resolved.  For modems (generally powered via the USB port of the computer) this is accomplished by rebooting the computer.  Depending on the quality of your router, it should attempt automatic reconnection when a signal is dropped, but the firmware may not detect the drop in all circumstances.  If you need to power cycle the router more than once a week then further investigation is warranted.  Occasionally leaving the power disconnected for an extended period (at least 30 minutes) can help force a remote server to drop a stale connection.

If the cause is still a mystery, it is first necessary to look for a cause close to home.  Do not skip this, as if an engineer is sent to investigate a problem that turns out to be yours, an invoice of about £160 will be raised by the line provider (usually BT).  Make sure that you have one (and only one) microfilter placed on every phone socket that is in use on the line that delivers broadband. This includes sockets used for phones, faxes, Sky boxes, security systems, extra ringers, modems and REN boosters.

Wiring or appliances. House wiring (including extension cables) and connections have to be good quality to minimise signal loss.  You need to eliminate house wiring from the possible cause and this is done by disconnecting all extension cables, phones, faxes, security systems, modems and satellite TV boxes from the phone system.  If you have a modern BT master socket (photo on right), simply unscrew the face plate and connect your router to the engineering test socket underneath (photo on left).  Owners of older properties may need to find the socket closest to the point where the phone line enters the building, plug the router in there and manually unplug all other devices.  If the problem is no longer apparent, then put your appliances back one by one to identify the rogue.

Ethernet cabling should be straight through ideally wired as follows 

Faulty hardware.  The only way to confirm this is to replace first the microfilter (just the one connected to the master socket as all the others should still be disconnected); if the problem persists, try an alternate modem/router (remembering to configure it first).  If you do not have a spare, contact 1ComputerCare for a loan one.

If the above has not resolved the problem, use your backup dialup modem or other PC to see if there is a problem with the local exchange by checking the exchange status at sites like Sam or PlusNet

Finally, contact your ISP to see if they are aware of a problem at their end.  For example, PlusNet provide a web page that you may be able to reach by using your backup dialup modem or you can phone them on 0845 1400 080 or use their online broadband fault checker.  They will probably initiate their own (Woosh) tests and take action depending on the results of that test - which generally takes 2 - 4 hours during which time your modem/router should be left switched on.