Joe Blow: Thank for your comment. It is done. andy256: Do you have any suggestion about how to rewrite the question? Thank you.

Thank you very much. It is very clear. For example, my mp3 player is broken or it has failed. In my opinion, I think having failed is more formal, broken is neutral, and busted is more colloquial?

Thank you very much for your answer. It is very helpful for me. ^^

Thank you for your comment. In fact I did several google search to clarify it. A present perfect tense which points to future rather than now? Or it is both acceptable to choose present or present perfect tense? It indeed is something new to me.

Thank you very much for your high-quality answer. It really clarifies an ambiguous concept of present perfect tense.