I do not know what electrical surge damage (which is what you describe)
Do you have a card reader? Maybe get one and try and read the card off your computer.
there are services that can retrieve data from memory cards which are expensive. There are some available on the web. Also call your top end camera/ photo lab, they are sure to have some ideas
here is one I found
FileRecoveryTools | Products | F-Recovery for SD™ Card
good luck