Thank you all very much for your help and suggestions.
The above from StaggS works only if you have an image saved in the printer memory already.
I was looking for a way of self testing the printer on the bench without any other equipment connected. I got the info I needed from Alan at AGX holdings, Sony repair agents at...
http://www.agxuk.com/ Thanks Alan!
As you need to access the service mode to do this I will post this info in the appropriate place.
Cheers - John