You can debrand the phone,it will remove operator logo and sounds etc. but it will not unlock it to all networks.
Read here about flashing A2 phones in sticky threads,battery must be charged so do that on another phone or use another battery.Phone must be OFF when you connect it.Read carefuly and follow instructions.
If it is damaged by water or some other hardware problem then it will not help you.
Check here: A2Uploader