I agree with the previous poster about checking the connection. You might want to also try cleaning of the pins or whatever you call them.
The a530 has separate psu, but it still doesnt hurt checking them.. It could infact also be the psu for the a530 itself. I got the gvp version without the accelrator myself and it behaves similar if i for example forget to turn on the psu for the gvp.
If you turn on just the a530.. does the hd power up and all?