If the phone won't boot at all, no download/recovery & not detected when you connect to PC, it's cactus, I'm afraid. Having said that, search for KingRat's 'jumpstart' method where you can try to get the phone going with just the charger/minus the...
The following is on Galaxy SII with Nova 2.1.1.
Before Nova 2.1.1 and while I was using Resurrection Remix JB v3.1.3, I had no problems like I describe below.
After I installed 2.1.1, a couple of my group folders were left with 2-3 a...
Maybe you'll get lucky wih the new version of EFS Pro that just came out.