Answer:
wishes
Step-by-step explanation:
An abstract noun is defined as that noun which cannot be experienced by the five senses, that is we cannot see, we cannot smell it, we are not able to touch it, we cannot hear it, we cannot taste it.
An abstract noun is an idea, a concept, an expression or a feeling. It is not physical object.
In the sentence given in the question, the abstract noun is "wishes" which we can only feel only. Here, wishes is only a concept that means the wishes in the world cannot make a broken phone work again.