The problem with these cars David is that the system monitors the supply voltage and operates safety cut outs to protect the electronics from undervolt conditions.
Unlike the old days when it became increasingly difficult to turn the engine over on the starter, giving you ample warning of impending trouble.
Ergo, "no indication of power loss" is an entirely possible scenario.
The symptoms of a low voltage detection are varied and can include various fail lights on the instruments and disabling of the starter circuit.
I have heard that an apparent total loss of electrical power is another possible symptom.
The first thing I'd try is either another fully charged battery or a jump start in which case the system will detect the 13 - 14 volts from the other car and will then switch off the safety cut-outs.
It's a place to start.
If undervolt is the problem you might want to consider the possible need for a new battery or the occasional trickle charge using something like the CTEK charger.
It is also entirely possible that, once power is restored, you'll need to go through the battery reconnection / reset procedure, the link for the document being given in this thread:- (Click directly on "Battery Reset Document) below.
As an afterthought, you will need to open the boot with the key in the mechanical boot release keyhole. If you don't know where that is, it's under the boot lip towards the left hand side. The key needs to be inserted vertically upwards.
Hope that helps.