PowerBook 1.67GHz (Hi-Res) FireWire ports aren't working, but System Profiler sees FireWire Bus.

Howdy everyone! I know this problem must mean a logic board replacement, but I really hope I can avoid that. Basically the title says it all. The FireWire ports (both 400 and 800) don't work for some reason. Every other port on the PowerBook does, and I just don't understand it. The System Profiler recognizes the FireWire bus and everything, saying:

FireWire Bus:

Maximum Speed: Up to 800 Mb/sec

However, it will never receive input through FireWire or provide output. I bought this PowerBook on eBay, and I believe that it may have been dropped before. I don't know if it has, it's just a hunch. Obviously fall damage would be pretty obvious in this situation, but it's stange to me that all other ports work and only both the 400 and 800 FW ports don't work.

Any thoughts? I've tried every resetting option available. I'm kind of at a loss right now.

Thanks everyone!