I assume you mean your BlackBerry doesn't power on. If it's under 1 year since you purchased it, it is still covered under warranty granted your claim is eligible for warranty repair. For example, water damage is not covered under warranty. If your BlackBerry is out of warranty (over 1 year), you can either buy another BB outright from Fido or through a classified ad service such as Kijiji.
Please provide some more details and specifics. The answer is: it depends.