Was the Battery still connected to the mainboard while it shortcutted? If yes, then maybe it is damaged. Otherwise, maybe the connectors are not really fixed to the sockets.

You don`t have to open a Galaxy, it burns open :D :D

What does the Festplattendienstprogramm says? Can you see the 4GB there?

Did you use a original HDD with apple Firmware or a normal HDD? If u use a nomal HDD with non apple Firmware, you have the Fan Problem.

Perfekt, es hat mich ziemlich genau 1 Stunde Zeit gekostet, hatte eine Disassebly Screw Template aus dem Netz geladen, sehr zu empfehlen. Funktioniert wieder alles wie gewohnt. Seeeeehr geniale Anleitung, vielen Dank, habe mir damit 100€ gespart.