Hello again RAF96 and Jane2 Thanks for your responses. Yes I had Hornby update the FW last year. So it flashes 16 and then 30 when I power up. I can then select any of my other locos as normal, but if I choose 06 for my Class 25, I can control sound but the 06 flashes the moment I turn the throttle. Jane2 asked if this happens even without the loco on the track, and the answer is YES. So I do believe that RAF96 may be on to something with the programme mode suggestion My 2 year old grandson has been with me for 5 weeks of lockdown and we’ve been “playing trains” a lot. He has a habit of pressing any available button. If you are correct, how do I get out of that mode? Powering off the Select does not seem to help? Many thanks. peter