@EdC
I'm sorry to hear you've had a problem but i agree with catymag that updating software from the card is usually very safe. I'm guessing that your unit lost power while updating or the problem is coincidental and unrelated to the update. The USB connections in most units can be repaired by reflowing the solder connections. Sometimes that doesn't help because the problem is on the board itself. Failed USB connections are a very common problem on xx and 1xxx nuvis, particularly the 5" models 50 and 14x0, but 30/40 and 12x0/13x0 and even 2xx/W can also suffer. I have a couple of units with re-flowed USB sockets which still charge but have no data transmission because of some other fault, probably failed component on PCB. I can backup and update everything including voices, maps etc by using text commands from the card, it's a little cumbersome but the units are usable.

Reflow first, and then if you still don't have data open a topic in Garmin Discussions and we'll talk you through updating from the card.