Is there any visible damage from the drop? If so, I'm afraid your warranty is void anyway, if not, it could be that there was a production fault with your player. I dropped my X-Fi2 once and I think it should be capable of surviving an impact, if it wasn't dropped from 10 feet or something else obviously damage inflicting.
If there's no visible damage and you've bought it at some shop you can try to bring it back, but if you have to send it in there is a chance that you will have to pay for the repair. So if the shop can't give you a refund or a replacement, I would try to fix it myself or seek someone who can. Google zen repair, or if you know how to handle electronic devices, try it yourself.
From looking at the Naked X-Fi2 pictures
the power button doesn't seem very fixable.. but maybe something has just gotten out of place and you can place it back somehow..