Thanks for your quick reply. I'm really sorry to hear how you feel. Like you I invested a lot - musically and financially - in the amp and have always been really pleased with it. In fact, mainly because of band changes etc, the amp hasn't been gigged all that much, which makes it much more "new" than its 2007 vintage suggests, which makes it even more frustrating. I had exactly the same experience as you - fine at a rehearsal, carefully taken home, no lights at the next use (which happened to be a gig). Interestingly, although the input lights had failed by the gig, I was still able to play the night by turning everything up full. Now, however, I can get nothing out at all no matter how loud everything is set. The fact I had a semi-failure first is odd - I guess it implies something was sort of failing one night and has since failed completely.
I have no knowledge of electronics at all, but the manual suggests the signal travels from left to right. I don't know if it physically does that in the circuitry, but if I'm reading the manual correctly, the signal is processed from left to right, assuming each component (valve, eq etc) is turned on. The fact the input lights aren't lighting therefore suggests that the problem lies right at the pre-amp/input stage rather than anything to do with, for example, the speaker connections. I really don't know what I'm talking about though to be honest, and I don't know how much help it is even if I'm right.
I'm going to do two things - I'm going to draw Trace Elliot's attention to this thread because I don't really think it is good for customers or the company if such an identical fault isn't even on their horizon. I'll ask again if it rings any bells too. Secondly, depending on what they say I'll try to see if I can get it fixed. Unfortunately, when I bought the amp I had a good job, and now I have no job, so fixing it is likely to be out of the question for a while, whatever Trace Elliot say. Unfortunately, although they have a generous three year guarantee, you and I seem to be just outside of it.