PCB Glowworm micron 50FF (replacement fitted)?

I have just replaced the PCB on my Glowworm micron 50FF but the boiler does not light. The old PCB appeared to be burnt-out and had 6 orange neon lights. The new PCB has 2 green neon lights (told it was an upgrade part). when the boiler power is switched on the boiler tries to start now (i.e water flow and fan), but after a couple of attempts the "Reset" light turns solid green and the "Burner on" light starts intermittently flashing green? can any one advise want to check / do next.