I tried with S4 mini but the same issue phone recognized ok by PC but USB debugging does not ask to authorise PC. Same on S7. I tried on different PC too, so now on both Win 8.1 and 10. Am I doing the ADB drivers right - I am just downloading USB driver from Samsung. Was 1.5.51, now I have .59 but still nothing. I just run the exe then the S4 or he S7 appear fine in device manager as Samsung USB device - so PC is seeing phone fine. Do I need to do anything else to install ADB drivers? Do I need fastboot or anything?
Yes, latest driver from Samsung website SAMSUNG_USB_Driver_for_Mobile_Phones.zip (15.3MB) 1.5.51.0
USB debugging is on.
Authorize laptop - I think so - I can browse phone directories in explorer anyway
Try going into Settings > Developer options > and click on Revoke USB debugging authorization & try connecting the phone to the PC again. You're supposed to get a popup authorization request.
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