Midas Sfi combi wont light?

I have a Madas Sfi combi boiler (20 years old i think) the problem is the hot water wont work. i run through the ignition proccess but it wont start,
ive taken the front off and the main control board is showing led 1 and 2 lit pannel tells me (will remain on until the fan produces enough air for complete combustion at low rate air detector.) and 2nd is high rate), any clues