Hi Pav. Like I said the other day, you should definitely get something when you plug them in ( eg work but flicker/ flash double speed).
When you say you have the cables are these def the conversion cables for retro fit? I'm just thinking if the cable wrong or faulty they would do nothing. I think all retro fit cables for e9x would be the same however.
If for some reason the cables are wrong you would get nothing as the connectors wouldn't be pinned properly.
It won't be fuses as your original lights work.
As Sam said the inners are still bulbs so should work. Could you plug the outers into someone else's e90? If they still don't work afraid they is ' knackered'.