I took delivery of my amp in June 2007, so it is over 2 years old so I don't think that legislation counts. That said, there is a law in the UK that says goods must be of a satisfactory condition to do the job they were intended for, and given I only really do a gig a month, this is not the kind of time period i would expect a failure in!!!! I may put a call in on that basis and see what I get but the nearest official service centre for me is in North London and that is a pain in the arse journey with a 50kg amp - even if I drove it would take best part of 2 hours to get there.
To be honest, it is such a straightforward job to replace the socket or 4N33 photodarlington (if that is the issue) that I can do it myself for less hassle than taking it somewhere and collecting it another day. I just didn't want to void my warranty if I was still inside the official one, given that if something more serious happened at a later time I would nolonger be covered.
Thanks for input - If I get anything interesting from Trading Standards in the UK I will post as reference for others whatever I do.
D