IF you could get an exact model and FW version of this model, you maybe able to just install the drives. I don't know for sure.
There are ways to extract the data from the drives depending on what you formatted the drives in. Standard or any form of RAID would make it a bit harder.
Does the unit remain on at all after turning it on? If you can get it to remain on, then try to copy the data off.
I would try to get the power adapter tested if possible.