If its not on, which might be the case, make sure all leads inside the pc are in properly and secured.
If yuo've checked this, and you see the ide cable going to the motherboard is twisted, put it in the right way (try that anyway, just inserting it another way).
This might be more the problem, as turning it off will be a safety feature if its in wrong.
You might find it will respond then
I hope this helps