| | Re: can't or won't?
In that context, neither. You're discussing a here and now fact which, in the context, can either be seen as a perment problem or a temporary one, depending on the speaker's perception of the event. So it would be :
- There's something wrong with the phone. It doesn't work - the speaker perceives the problem as permanent
or There's something wrong with the phone. It's not working - the speaker perceives the problem as temporary.
will expresses a prediction, so the conversation might continue something like :
A : There's something wrong with the phone. It's not working.
B: It's not plugged in. It won't work if you don't plug it in!
Or, in another context, imagine a meeting in a company which is discussing how to increase income.
A : I think we should increase our prices.
B: No, that won't work. We'll just lose customers.
As for can't, here the concept is "impossibility". Imagine that some new technological product has been announced and someone says : It's a good idea, but it can't possibly work in the way they say because ....... - ie it's not possible for it to work like that