Fixing a broken hard disk

A few days ago my external UDB 60MB Lacie hard drive died, it does nothing just tirns on the light when connect. Since its way over the warranty period, I opened and found a Samsung disk inside, tried to connect it directly to one of my laptops but nothing, its dead.
I can't even run utilities such a Spinrite because it remains undetected by the BIOS.
What next?
I found the same exact disk on e-bay a bought it, when it arrives I'll try swapping the boards between the two and if the problems are in the electronics it should work. Electronics have no soldering now and can simply be unscrewed and replace. I hope in some good luck...