It MAY be time to kiss your data goodbye, or, consider contacting a recovery service.
Watch the drive lights as the unit powers up - do they both flash initially? What does the other drive light (the one that does not stay flashing) do - does it come on and stay on, or does it stay off?
Pull the drives and power the unit on - what you are attempting to do here is to determine if the problem lies with the unit or the drives - the unit should, assuming you are using a recent firmware version, boot all the way up without the drives, and you should be able to access the admin webpages.
If it does not come all the way up, you probably have a defective unit, and MAY be able to retrieve the data by installing the drives in a different DNS-323 - I have not tried swapping drives between the 323 & the 325, I do however recall reading (on these forums) that the formats are different - and if you value the data, I suggest you not fool around with the drives as your attempts could further jeopardize the data.
I would also suggest that you look into the methods available for backing up your data and start doing so immediately - whilst you're about it - get rid of the RAID0 array on the 325, a RAID0 array gives you no more storage than two separate drives, but has twice the risk of data loss.