iPhone lock button doesn't work and is displaying only apple logo

is your phone charging at all when you plug it in to wall charger? if it isn't charging and isn't recognised in itunes then try cleaning the USB port of any dirt and debris, then try again with itunes. Next step is to check that your USB cord is clean and undamaged, try a different connector and USB port. You could try using tinyumbrella to see if that programme recognises a phone in recovery mode..you can use it to exit recovery. or you can use iReb for the same thing. If that doesn't work then you may need to change the battery or the dock connector. It is more likely the battery if you have been experiencing problems with random crashes or poor charging life/prolonged time for charging. It's worth changing the battery at the same time as the dock connector as then you know you have 1)known good power source, 2) battery is nearly at the end of it's life if it is original to the phone. Once you have done these things try and restore the phone.