caravan battery charger problem

hi all, whilst on a few days break we accidently tripped the electrics in our swift carisma 230 ,this resulted in our battery charger  not working, could we have blown a fuse in our charger ???? if so is there a clever person out there who could explain how we do that repair,OR do we need a new charge unit fitting ( i guess this will be very expensive too) thanks all. happy caravanning