hello
you had a dose of poor judgment and bad luck in this endeavor; I am sorry to say
but, lets look for a silver lining
remove the Lacie drive from the enclosure and try connecting it internally to your computer / remember to set the jumpers as needed
I personally would use the cable from your cd/dvd drives and have only that Lacie drive connected on the cable while you check things out
remember; you dont need to get all fancy and proper about mounting )fastening) the drive into your computer >>>>> you only need to place a phone book next to your computer, lay the drive on top of the phone book and connect a data cable and power cable to the drive , then boot the desktop computer and keep your fingers crossed that you only need to replace your external enclosure
if thats not the case >>>>> then you "can" replace the PCB (printed circuit board) of the lacie drive. thats the little computer board on the bottom side of the drive which the data cable gets connected to, these are held in place by two or more small screws
DONT open the drive case itself or you will lose all data guaranteed !!
to get a replacement PCB you will need to contact Lacie and do a little begging or they may give you a contact for their parts distributor / this approach has worked for me several times