Try the *#7370# reset code and if that does not work try the deep reset.
Always remember to backup your phone before performing resets as your data may be lost.
Then try the "3 finger deep reset". With the phone powered off, depress and hold these three keys simultaneously "*" "3" "green phone" and then power on phone using the on/off button whilst keeping the three keys depressed until you hear start-up tone.
The only other thing you can try yourself is the 3 finger reset. You will lose all your data unless you have a previous backup. That is why you should backup your phone regularly.
If you saying that you have tried (*)(3)(green) depressed whilst pressing red (power key) perhaps you should look at the different key configuration required for "hard reset" on E72 a similar S60 3rd FP2 device.
Symbian specialist until 31/01/2013 with interests in Maemo & MeeGo but an aversion to Windows!
If i have helped at all a click on the white star below would be nice thanks.
In all the years that I have used a Nokia phone, I have had a 20% success rate with these so called "hard resets." I wonder fi they even exist!
I'd try doing a firmware reload.