I wonder if you've spilled some liquid at some time onto your firewire ports while the laptop was powered up...common method of short circuiting the BUS which controls the firewire ports....a question...is your wireless signal strength bar still showing on the menu bar? they are both related...if that wireless signal strength bar has disappeared and your firewires have no power...the BUS on the logic board that controls them might have shorted. If so, a new logic board or second hand one is the only way. If you do that, make sure you are careful with the ambient light sensor when you remove it...very delicate and easily damaged...it controls signal to backlighting of your keyboard...
Many of those external hard drives wont get enough power from your usb...the one on the left is high speed ....if you were to connect to both usb on left and right then there should be enough power....firewire 800 or 400 supplies power to external drive or isight camera if functioning.
The most concerning part of no firewire is that if your hardrive fails you cannot reboot from external hardrive onto which you may have backed up....would need to reinstall OS X and then copy back info...if you have firewire working...you can back up to external hard drive through it and and boot from it if you desired...very very important function for the longevity of your laptop....