Death PCB

[Bruno]

Hi all

i become a Maxtor Calypso from client, with dead PCB. The cient says, he connetcted the Power wrong way. On the PCB, i dont can see any broken Chip. I dont found any Fuse. So i resolder the VoltageRegulator Q501 from another Maxtor.
But the PCB dont work.
The problem is, i dont have the exact PCB. I think the +5 V Conn. are connected to 12V. So, what Piece of the Electronic Board can be faulty and i should replace with new one?

Very Thanks
Bruno