Prius C blown fuse

I have a 2012 Prius C, I’ve had it for about 2 weeks, I just bought it from my mechanic (I’ve bought several Prius from him and so have many of my friends and family) everything has been fine, no problems. I turned off my car for about 5 minuets and when I got back in, the car wouldn’t start. The dashboard lights and everything came on but when pressing the break, it wouldn’t turn on completely.
I tried jumping the battery which of course didn’t work, I called my mechanic and he came out to look at it and said it’s likely a blown fuse. He’s taking it back to his shop to take a closer look.
My question is, how would blowing a fuse like this happen? Is this something I did wrong or could have avoided? I don’t drive a lot but I do always have eco mode on, but I don’t use my AC ever or anything else. Or is this just something that happens sometimes?
The car was salvaged, he buys salvaged Prius’ and rebuilds them, and like I said every one that I’ve had has been perfect as well as the others my friends and family have gotten.