Fixing a Baxi 105e Combi?

In November 2006 had a fan/flue light flashing on my 105e, chkd flue ect and all ok. while putting tools away driver slipped off slipped of the top and in catching it I banged the side of the unit, this kicked burner into life. Tried this a few times when it didn't fire up and it worked every time. changed presure switch still same prob so ordered new pcb Part No: 5112380 (was 248074) changed over found conection A1 was opposite way round A3 has been moved to where A4 was with A4 movied forward plus new connector A9 added. connected all up nothing working got different led's on. Spoke to supplier who said send back for replacement. In meentime put old pcb back in, wouldnt work, in frustration slamed control cover shut and walked away. Sat down then realised heat coming from rads. The 105e has been working perfectly since then untill 2 days ago, same problem fan led coming on. As I had replacement pcb from last time still unopend decided to swop it out same board as last time so can anyone tell me if this correct or are there differrent boards in the 105e. I have photo's of both pcb's if any one needs to look at them.