It sounds like a broken microusb port but try something first.
Download ubuntu or any other live cd linux distro
Boot it on your pc. You dont need to install anything.
Open a terminal
*Plug the phone while it is turned on to the PC
Write in the terminal 'lsusb' without the quotes and press enter
Something like Samsung android device or MTP device should appear.
If it doesnt appear power off the phone and go to odin mode and repeat from the * the steps
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