Hi, welcome to HWF.

If I were you, I'd try to identify the failing component on the PCB, since the possibility that every component on the board failed is slim. Plus, you'd be sacrificing your brothers HDD to (maybe, perhaps) have a shot at saving yours... doesn't seem worth the gamble, really. But if it's one shot resister or a melted solder path or something relatively simple like that, you might be able to fix it well enough to get your data off.