WD mybook 500g doesn't show up

so a while ago i ran out of HD space on my ps3 so i got a new HD to put in it but first i backed it up with my WD mybook 500g (the one with the green ring on the front) which i had to reformat (i dont remember what format it is now) and the HD upgrade went fine as well as the restore from the back up but when i plugged the mybook into my macbook pro it didnt show up at all..not even in disk utility or in disk warrior so i tried it on my windows partion (win7 if it helps) and it didnt show up there either so im wondering if anyone knows how to fix this
all help is appreciated and sorry about grammer/punctuation im just lazy..if you want me to type normally i will