mac pro 1,1 issue with boot up

[krumky]

hey guys,
i recently plugged a usb hub into my mac pro, this caused the mac to turn off for some reason and now every time i try to reboot the mac it starts to load then turns itself off again, i've tried all i can think of to fix it but I'm running out of idea's.
i believe that the cause was the usb hub was too powerful and it could have harmed the motherboard?
thanks guys

 

[gsahli]

When and How to Reset Mac SMC (System Management Controller)
(follow the PRAM link in there, too)

 

[harryb2448]

From your description which is pretty vague it sounds like you are using a hub that draws power from the host machine? USB hubs are not that great generally, but look for a mains powered model if it is a machine powered hub.