i've been in a battle of wits with this damn phone the whole evening..
it is a i747m, on 4.3 with Bell
this is what happened:
i flashed a stock, pre rooted firmware (stock) from here
I went into the stock recovery, did a factory reset, wipe cache and got the following error (pic attached)
now every time i boot it i does not get back the sammie logo..
i tried flashing twrp, cwm, flashing a custom rom, getting it back to stock stock, then pre-rooted stock.. nothing..
also, when i try to wip data from any custom recovery it says cannot mount data..
anyway.. this is the situation.. im afraid the internal storage might be corrupt or something.. so if you have insight on this, please do share xda-san