Unable to access device storage

[AC Question]

Samsung Galaxy Tab 10.1
Android 4.0.4
Build 3.1.10

Symptom 1
Tablet no longer allows access via Windows.
When I attach the tablet to my Windows 10 PC via USB the system no longer recognizes the tablet.

Symptom 2
Android My Files app no longer works
When attempting to browse files using My Files (previously have been able to do things like see what files were in which folders, rename files, move files to other folders etc), app starts but never displays folders or files, just displays the animated loading whirly.

Symptom 2
Other apps that should be able to find files in the local storage display similar behavior... One Drive, or trying to attach files to email.

Symptom 3
I downloaded an MP4 from thei nternet (legally) for viewing whennot connected to the network. By default the file should end up in the Downloads file (though obviously I canmot confirm that this file ended up there this time). Notification area displayed a mesage that the download completed. Normally the video app, when started, scans the local storage and adds any new videos to the display. One video, located in the downloads folder, does show up in the app. The video newly downloaded, however, does not show up. By this I conclude that the video app is unable to rescan local storage.

Additional data

I have made no modifications to the Android system.
No new apps have been installed recently.
A number of months ago I had a memory issue where files deleted from local storage did not increase the available space. I eventually resolved this issue by doing a factory reset.

I am resigned to doing another factory reset if there is no other solution, but would prefer to fix, as I cannot determine exactly which files I would need to find from sources or from my PC (everything stored on the tablet was loaded from the PC or downloaded from legal sources that I would have to track down - not a deal breaker, but a pain to have to remember and find it all).

I also know that it is about time to replace this tablet, as I have had it for about five years. On top of everything else I cracked the screen last month. But that requires spending money I don't have at the moment.

All that said, I would appreciate any tips toward making things right.

Thanks in advance!

 

[Rukbat]

1. "Normally the video app, when started, scans the local storage and adds any new videos to the display." is wrong. Copying or opening media apps doesn't rerun the media scan, only starting (or restarting) the phone or running an app like media.Re.Scan (or running a camera or recorder) does.

2. Sounds like a motherboard problem to me, but you could try (in order) an app cache wipe (settings/storage), a system cache wipe (boot to recovery) or reflashing the ROM.