The Tone Ringer will not work at all.

First of all make sure the Tone Ringer is turned "on" at the switch on it's front panel and that the volume control is turned at least half-way to maximum loudness.

If it's a new installation:

Incompatibility with the host system or telephone is the usual cause that a newly installed Tone Ringer will not work at all. Follow this procedure before you do any further tests to see if you are triggering the tone ringer with a "standard" ring-signal. If your analogue test telephone will not ring the Tone Ringer is never going to work in your application. If your analogue test set works OK and you are using the inbuilt speaker, make sure the speaker leads are connected to J3 and that J1 is set to "Internal". If you are using an external speaker, make sure that J1 is set to "External". If J1 is correctly set, try using the internal speaker - if this is OK you've got a problem with the external speaker or its connections/wiring. If these tests do not isolate the problem, it's likely that the Tone ringer will need replacing.

If it's a previously OK Tone Ringer has suddenly stopped working:

First check that the tone ringer is switched "on" and that the volume control is turned up. If you are unsure if a ring-signal is being received, follow this procedure before you do any other testing. If you are using an external speaker, try using the internal speaker - if this is OK you've got a problem with the external speaker or its connections/wiring. If both the internal and external speakers will not work, it's likely that the Tone Ringer will need to be replaced.

Note:
If you can get a T200 or a buttinski to ring on the circuit you want to connect the alarm to, the Tone Ringer will work OK. If the test telephone/buttinski won't ring, neither will the Tone Ringer.