If your phone wont switch on, then it doesnt sound too promising.
One thing to try is to take out the battery, then press and hold the ON button for about 10 seconds or so. Replace the battery, then press ON button to start it. This is a soft reset, and wipes the temporary memory and empties all remaining power in the circuits.
If this does not work, do as above but after inserting the battery, press and hold the ON button and the HOME button at the same time for 10 seconds or so again. This is a hard reset, and works best if done after a soft reset.
If neither of these works then you phone seems likely to be bricked.