I have the same problem with my s4 clone, it start normaly working but shutdown after load menu... and again, again. I cant do anything because phone shutdown in 3 seconds after load start menu.. I can run phone and see wallpaper but after this system shutdown. I can open "Factory mode" and "Select boot mode" but I dont know what else. In factory mode smartphone didn't restart!!! I think that's fault of android - not phone.
I tried upload fresh soft SP Flash tool (I found - i think - suit to rom for my phone) but after click download and connect phone nothing happend - I dont know why?
Maybe you find some solution for this problem?
[SIZE="2"][B]X8 > Samsung i9000 > Asus Transformer > Samsung gt-p1000[/SIZE