my myson apollo fanfare 30/50 Si boiler will not light?

the power supply was turned off without the boiler being shut down. after this it would not re start, did not make any attempt no clicking trying to fire up left boiler switched off overnight and it started 1st time. It ran for about 1 hour then shut itself down and then unable to re start again. { am I over looking something ie re set button ? is there one } The fan has been taken off recently could it be that it was not sealed properly when re fitted.