baxi boiler 80e wont fire up?

can anyone help ? i have a baxi boiler 80e that wont fire up have tried to locate reset button but it doesnt seem to have one unless i'm blind !! it seems to go through the fire up sequence when u turn reset knob on the front control panel then the red neons flash for flame failure and fan/flue,the fan seems to be working ok as i have checked that,anyone got any ideas what to do ??