How to recover Datas on WD Home 2 Duo 4To electric damaged

I bought a device, and it didn’t power on since i had an electric damage.
I would like to recover my datas, then i connect 1 of 2 disk to my Windows pc with usb connector, i use a linux partition application and read disk.
But in all folders, i only found thumbnail of my photos.
What is the good way to access data ?
Buy an other WD Home duo without disk and insert my old’s in ?
Please tell me it is possible.
Thanks to all.