A/C Adaptor orientation for ccd trv78e Handycam

[phil51]

Hi I hope someone can help.
My daughter and son in law have just emigrated and left me with their ccd trv78e Handycam.
I have been left the A/C mains transformer, but not the mains cable to go into it.
I have another mains cable which will fit, but it is a figure eight shape and will go in either way round.
The socket in the transformer has a flat edge on one end so the original cable can only be put in one way.
With a lot of electrical items that have this sort of cable, the socket is a figure of eight as well and the plug can go in either way round and the electronics must sort this out
But i imagine with this cam it should only go in one way.
I can get a mains tester and see which of the two pins is live, but i don't know if the side of the socket in the cam with the flat edge is live or the other round edge
Can anyone help as i dont want to ruin it by reversing the connection or really spend about £30 for a complete new one
Thanks in anticipation
Phil
I've just realised I have put this in the wrong section and cannot see a way of moving it, sorry