HI SINCE I got no replys I will ask again MY sim 420 packed up on friday night. THERE is power on when I switch it on the fan start up but tubes dont come on I have it from new IT is only four mts with about 250 hrs use. I have contacted the firm I bought it from. They will call out to me next. WHAT I wanted to know has anybody else had trouble with this model. I know it is still under guarntee. but it looks it back to the factory. THANKS MUD.