Slight chance of working but easy enough to try.
1. Go to settings then apps and find the clock, clear data and cache for app.
2. Reboot phone.
3. If that fails try one of the many alarm clocks from Play Store. If those don't work then consider the more drastic steps listed in above post.
Last edited by adfurgerson; 25th June 2014 at 04:56 AM.