Navigation/Audio not working after jump start

Hello audiownersclub.

Hi, please can anyone advise. I had a flat battery and attempted a jump start last week which didn't work and the jump leads went hot while smoke was coming from the connectors. I have been advised this indicates the battery was dead. Disconnected the battery to try to trickle charge but this was unsuccessful. Got the car started on Friday anyway by the breakdown people but the RNS-E nav/entertainment system won't switch on. I thought it was likely to be a blown fuse but I pulled the fuses indicated in my manual under the hood and they seem fine. Also looked for the one inside the car but the space is blank and there is no fuse there. Can anyone confirm what is likely to be causing this?