I have the same issue, and seem to have come across the fix.
When my micro SD card stopped working / randomly unmounted, I checked Device Manager. In Device Manager under Storage Controllers, the SD Storage Class Controller for the SD slot was disabled.
What is happening, I think, is the system is putting the SD slot to sleep to save power (whenever it feels like it).
To fix, in Device Manager (right click or long touch on Windows logo in bottom left of screen, choose "Device Manager"):
- Scroll to bottom and expand "Universal Serial Bus Controllers" (USB)
- Open property page for "USB Root Hub" (or similar). You can open by double clicking or long touch and choose 'properties'.
- On the "Power Management" tab, uncheck "Allow the computer to turn off this device to save power". Click ok.
- Close Device Manager.
- Hopefully this fixes it
I am testing on my device now...so any confirmation that this works, please share.
This didn't work for me.
I did something that is not a fix but makes it less of an annoyance.
I turned off what windows 10 does when you insert a new micro sd card.
In setting under "Devices" >Auto play >Removable drive set it to "Take no action".
Memory Card set it to "Take no action"
I also turned of both the sound when you insert a new card and the sound when you remove a card.
I still get a can't write error occasionally but by the time you save again the drive is already awake.
No more explorer windows popping up, no more mounting and dismounting sounds but like I said, not an annoyance but NOT a fix.
I'm really tired of this problem and I've tried just about everything. Including turning of the option to let the drive go to sleep.
cheers,
james-