Iphone 4s black screen but i can hear the charging noise?

It won't start up but when i plug it in i can hear the ding for the charging noise repeatedly on intervals! I tried a hard reset and it stopped for a couple seconds (i'm assuming while it restarted) then started with the noise again! If called you can hear it ringing (from the other persons phone) Help?!

Has happened to me before. Plug it in and leave it like that overnight. The next morning unplug it, leave it for a few mins then try turning it on. If it doesn't work, your phone may be history