I have Samsung Galaxy S2. The Bluetooth of the phone has stopped detecting any Bluetooth devices around. It was working fine till last night. The phone got switched off during the night due to a low battery. When I charged it in the morning and tried to connect the Bluetooth, it turns on and when I do scan devices, it says no Bluetooth devices found although there are Bluetooth devices present.
Well, that's weird. First of all, make sure that the other Bluetooth devices you are searching using the S2 are visible. Otherwise, it's not going to detect the Bluetooth device.
And if you are sure that the Bluetooth devices you are trying to connect are visible, try clearing the cache and the data stored by the Bluetooth app, you can do that by going to Settings > Application manager > Tap the Bluetooth app, and clear the cache and the data store.
Now try connecting with the other Bluetooth devices and see if that works out or not.