my mac SE problems

ok, so i got a mac SE off ebay, for a decent deal. now a logic board, floppy drive, CRT tube (I let the magic gas out of the first one) later, im back where i started. i write a boot disk with my powerbook 1400cs, pop it in. it boots up to the system software. i go to hd sc setup like i did when i used my external floppy to boot, and it shows nothing. the first time, i got to boot with an external floppy and the old logic board, and it showed the drive until i attempted to format it, which it wouldnt. after that, i couldnt see the drive again, and my boot disk kept getting wiped each use, and id have to reload it. so then, i replaced the board, the CRT, and the floppy, and now its still doing the same damn thing as it was before. is it possible i need new or replacement SCSI and floppy cables? its just being really weird.....