If your phone doesn’t boot into download mode and you have a black screen after flashing froyo heres how you unbrick it.

Step 1 – Prepare odin with the firmware u want to flash (in my case was gingerbread 2.3.3) and get it ready to go;

Step 2 – Remove battery, SIM and SD card, next connect your galaxy ace to the computer;

Step 3 – Hold Volume down + Power + Home button at the same time;

Step 4 – Insert the battery and wait a bit;

Step 5 – At this point Odin should have detected your SG Ace ( Yellow rectangle should appear);

Step 6 – Click Start button in Odin and wait about 5 min.

If all goes well it should come back to life.

Roms from samfirmware:

PS. The correct European Froyo firmware is this one:
http://hotfile.com/dl/112095746/7fef9f5/S5830XWKB7.rar.html
or
http://hotfile.com/dl/111959706/1f7adaa/S5830XXKC1.rar.html
Don't forget the cooper.ops file of course:
http://www.multiupload.com/N1TQ49HORW

Password: samfirmware.com