Samsung s5360 notification bell suddenly becomes smaller, how to set it larger?

First turn on the settings, then turn on the sound, and then find out the volume. Three sound settings will be displayed. Select the second media volume and adjust it as needed. I hope I can help you.

I suggest you go to the repair shop. I can't help it However, when you go to repair it, you must pay attention to whether they have tampered with it. I hope I can help you.