. It can also stem from power delivery issues or degraded battery health. Apple Support Community Primary Fixes for Error 75 Use Quick Flash with "Fix Battery Health" Open 3uTools and go to the Smart Flash Select the Quick Flash Mode (note: this will erase data). Check the box for "Fix battery health"
If you are getting the error while in standard Recovery Mode, try switching to . 3utools error unable to restore idevice75 link