No dash lights or numberplate lights

Evening all - a frustrating issue with my 2008 9N3 - a 1.4 Bluemotion. 

Short story, I noticed I had a tail light bulb out, so thought I’d replace with LEDs. Fitted them and they worked, but noticed the numberplate lights weren’t working anymore. Drove the car that evening and found none of the dashboard lights up. Everything still works, it’s just not illuminated any more. 

I’ve had a quick check of the fuses and can’t see anything out. The LEDs have been replaced with regular bulbs. I had LED numberplate lights which I’ve replaced with regular bulbs too. 

I have a new headlight switch on it’s way, but wondered if anyone had seen this before or had any ideas. 

Thanks 😊