not ring reliably

I use the egg timer since May this year. So 6 months. Meanwhile, the clock does not ring more reliable. At first I thought it would be due to the voltage of the bell, so I always put on the clock on 60 minutes and then put back my desired time. Without Success. I noticed the non-ringing usually only because I did not hear the loud ticking of the clock.

Conclusion: As nice as the egg timer is not that they should stay in the kitchen with no function.