domini99, tried already to do that. Without success
domcale, the app "Galaxy Ace Unlock" made a backup of /dev/block/stl5 (called "stl5.rfs") which I found on memory card.
If I can't boot up in system/CWM/Recovery and I can enter in Download Mode, what this means?
Mmmh. But are you sure kies is installed and kies usb drivers?
Check that and reinstall all kies junk, then try again.
If it wont help i gues there is something else broken than your android os.
Sent from my sending thing...