The guy from Exclusive Repairs was excellent. I didn't catch his name, but would like to know it as I would ask for him in future if I need a repair again. He tested/disconnected everything but couldn't find a fault, and was slightly distraught because he didn't like not being able to resolve the problem for a customer - a very good attitude. He know his stuff very well, and concluded it could only be a computer problem, a repair which was not really cost effective compared with buying a new machine. In fact, since he reconnected everything, the machine has been working perfectly, so perhaps he did unknowingly resolve the issue after all. We'll have to see if it crops up again.. Excellent service.