How Can I Fix my Boiler Baxi Solo 3 PFL 40?

My boiler Baxi Solo 3 PFL 40 as stopped working, all the lights light up when turned on i.e.

Boiler : Light on
Fan : Light on
Pilot : Light on
Burner : Light on

The pump is working but the Main burner doesn't seem to be firing up.

Please help me. Thank you