ReadyNAS 10200 won't turn on after moving it...

Hi, Bought this unit just over 2 years ago and inserted 2 western digital drives and set them up to mirror each other. All has been fine. It's being used to back up photos, music files and work documents. It was only on whilst being used, so has had relatively light usage. We moved it last week (turned off properly) and since plugging it back in it won't switch on. The power button on the front does nothing, no lights and no sound. Not sure if it is the AC adapter or the unit which has failed. There are no LEDs at all on the adapter itself to indicate whether it is functioning. I have tried different sockets, a different kettle lead (which I know works), and checked all connections thoroughly. There seems to be an LED (or a hole?) on the back of the unit itself labelled SYS, should this light up if the adapter is working? Basically stumped as to why moving this across a room would prevent it from turning on again, and don't want to buy a new adapter if that is not the issue. Have had a dig in our old wires box and I don't have another adapter with the same power ratings. Could really do with accessing the files on it too! Any advice greatly appreciated. PS. I am a bit of a novice, so apologies if this is a simple to fix problem (really hope it is).