How to backup frozen iPhone7 on logo

My iphone 7 is frozen on logo and i couldn't use any of the methods . I tried force restart and recovery mode but it does not update and gives an unknown error. My data are really important and i cant back up right now. Is the problem from connector? Before getting frozen I tried to back up data on computer but that didn’t work too because of an error called ‘device has been disconnected. I also tried iPhone to iPhone transfer but it also ended up error of disconnection so i tried to turn the phone on off and on then it frizzed on logo.