Broken 746 telephone

[boombox]

My father in law has dropped his 746 telephone.

Now, it sits and hisses and crackles and gives feedback through the receiver even when the phone is on cradle. It does sort of work, although ringing on incoming calls is now a bit stop-start and struggles to get going, only really properly ringing a good 6 seconds or so into an incoming call.

I'm wondering if anyone knows what could be done to sort the problem?

They'd be quite happy to convert the phone into a bellset only if all else fails, as they've gone over to a cordless handset in the meantime but the ring on the cordless handset is woeful!

[Nickthedentist]

They're very simple phones, and I think you'd be able to find out what's wrong if you took the cover off.

Look for cracks on the PCB and the ASTIC ("transformer") wires pulling away from their solder terminations; the expected DC resistances are printed on the ASTIC.

You may have more than one fault, so examine the bell "motor" too.

N.

[pip5678]

Following from #2 the mechanism from the cradle may have been disturbed upsetting the switch hook microswitch operation.

[Nickthedentist]

Good point. In fact, that's the most likely explanation by far.

[Dave Moll]

Originally Posted by boombox

...ringing on incoming calls is now a bit stop-start and struggles to get going, only really properly ringing a good 6 seconds or so into an incoming call.

I wonder whether the eccentricity of the bell gongs has been disturbed so that they're no longer optimally positioned for the striker - particularly whether the bolts have come loose and the gongs are no longer firmly held in one position.