MAC Pro not seeing external hard drive

[prophotomac]

My Mac Pro (OS X 10.5.8) was connecting to my LaCie external hard drive up until a few weeks ago. Now it does not. The profiler does not see the fire wire devices. I tried a USB and still nothing. But it works fine on my Mac laptop.
Advise please?

 

[simsaladimbamba]

Have you tried an SMC reset yet?
Intel-based Macs: Resetting the System Management Controller (SMC)

 

[prophotomac]

Yes, I have tried the SMC reset.