isolation test

An isolation test involves isolating a single piece of equipment on telephone line. This can be done for modems and telephone handsets.

Isolation tests are performed to determine if there is a fault with equipment or a line. By isolating the line we can discount outside sources of interference that could be causing the fault.

Isolation testing involves removing all sources of telephony equipment. This means that all telephone handsets, EFTPOS terminals, dialup modems, back to base alarms and foxtel digital services as well as filters should be removed from the line.

If possible multiple phone cables (of no greater length than 2 metres) and multiple handsets/modems is also a good idea to have available for performing the test.

Once you have all the equipment the test can begin.

Modems

Take a single piece of telephone cable and connect it to the modem without any filters. Look for the ADSL synchronisation LED to become solid. If it does not hold solid retry the test with another piece of phone cable.

Should this test pass then you can readd a piece of equipment to the line one piece at a time. Check for ADSL synchronisation each time after you add the piece of equipment. If the LED dims it can be safely assumed the last piece of equipment is causing a fault.

If the test fails then proceed onto the next socket in the house. If there are no other sockets a good measure is to test the modem at an alternative location that has ADSL broadband. All that needs to happen in this test is for the LED to become solid. If this is the case you can be sure it is not your modem at fault.

Telephone Handsets

Take a single piece of telephone cable and connect it to the handset. Check for dialtone or any tone on the line at all.

Should this test pass then you can readd a piece of equipment to the line one piece at a time. Check for dialtone each time after you add the piece of equipment. If dialtone is lost it can be safely assumed the last piece of equipment is causing a fault.

If the test fails then proceed onto the next socket in the house. If there are no other sockets a good measure is to test the handset at an alternative location. All that needs to happen in this test is for the handset to have dialtone. If this is the case you can be sure it is not your handset at fault.