Ah those of little faith!,
Removed front adjuster screw from the coil (once I had marked it and counted screw turns to remove)
The screw is plastic and had a molding tag at its end (which looked well and truly squashed) - removed this tag and refitted back to original position (did not work)...
Thanks guys for all your suggestions, boiler man came and replaced the PCB card for a second time and the fault was still there!!!
Don't know if I found an 'iffy' boiler service engineer but he did not know what to do next.
I read the manual and tried the water to see if it had the same fault...
Boiler out of action now for two days and its cold!!
I've checked the pressure switch which is Ok, The electrode is sparking ok and there is gas flow - but that just stops as if there is a safety circuit cutting in.
The baxi manual does not list this fault - doh.
My local engineer has been...