MicroSD card randomly unmounts itself

Have had my Surface 3 for about a week. Installed a new Samsung EVO 128gb card and am having the same problem. Tried, tape, format both exFat and NTFS, changed policy with no luck.

Chatted online with MS tech support. From shut down they had me do what they called a Forced Restart, holding down the power button and volume up button at the same time. The tech assured me that would fix the problem and, of course, it didn't.

A second chat with them and they offered to replace the Surface. This card worked on my Dell laptop with an SD card adapter with no issues. It would seem that this is an issue with the Surface hardware but it also seems doubtful that a new one will fix the problem. Despite liking the Surface I am leaning towards getting something other than a Surface.

I've had the same issue with many types of brands from Samsung to Sandisk to Transcend etc. All these cards work with other tablets just fine but on the Surface, unmounts literally within minutes, ejecting then reinserting gets it going temporarily but not to the point where it is reliable opening a file from it. Lo and behold I come across this brand of microsd's http://www.amazon.com/Silicon-Power-MicroSDXC-Class10-SP064GBSTXBU1V20SP/dp/B00TB8XZOK/ref=sr\_1\_1?ie=UTF8&qid=1444258118&sr=8-1&keywords=silicon+power+micro+sd

Not only cheaper than the others but I have not experienced any unmounting since purchasing, going on about 2 mos now. Not a household name but works and is fast. I'm in IT and a co-worker bought USB 3 drives for our group by the same brand. I was impressed at how well they worked and their speed. Figured worth a shot trying their microsd's, if they weren't any good, I could just return them. So far so good and I think it's my answer for the microsd card problem everyone seems to have. I don't know what makes these different from the others but they work. How good they are long term, don't know but for now worth the risk and so far very happy. I'd recommend taking a stab.

I know others have asked this question, but I haven't seen a clear answer in any existing post. The microSD card in my Surface 3 (Win 10) does not stayed mounted. If I take it out and reseat it, it comes back but after a few seconds will disappear. Based on the postings I've read, this seems to be a known problem but I'm not seeing a resolution. I call MS next but am wondering if anyone has a clever way to fix this problem.  Thx!

I have a Microsoft Surface 3 BIOS Version 1.50410.78 Date 03/10/2015 with 4GB RAM, 128GB HDD and a Type cover, running a fully patched version of Windows 10 Home x64. This was updated from the original Windows 8 installation. I have inserted a 128 GB Class 10 Lexar MicroSD card formatted as exFAT in the microSD card slot. The card works for a while and then is lost from Device Manager. This happens sometimes when the Surface is in use and more frequently when restarting the Surface from Sleep. From Device manager I can see that the SD Storage Class Controller is using a Microsoft driver dated 21/06/2006 version 10.0.10240.16384. This seems quite old and I wondered if it is indeed the correct and current version of the driver for the Storage Controller?

If there is a more recent version of the driver where can I obtain it from?

Since installing the Micro SD card I have 285 Error entries in the Event Log similar to this one:

Log Name:      System

Source:        disk

Date:          24/08/2015 18:18:08

Event ID:      11

Task Category: None

Level:         Error

Keywords:      Classic

User:          N/A

Description:

The driver detected a controller error on \Device\Harddisk1\DR3.

Event Xml:

<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">

  <System>

    <Provider Name="disk" />

    <EventID Qualifiers="49156">11</EventID>

    <Level>2</Level>

    <Task>0</Task>

    <Keywords>0x80000000000000</Keywords>

    <TimeCreated SystemTime="2015-08-24T22:18:08.813117800Z" />

    <EventRecordID>5399</EventRecordID>

    <Channel>System</Channel>

     <Security />

  </System>

  <EventData>

    <Data>\Device\Harddisk1\DR3</Data>

    <Binary>0304800001000000000000000B0004C00301000000000000000000000000000000000000000000004201010000000000FFFFFFFF060000005800002400000000FF200A124C022000000000003C0000004060D2F401E0FFFF986711F701E0FFFF0000000000000000C08DADF401E0FFFF009D0FF701E0FFFF000000000000000028000000000000000100000000000000000000000000000000000000000000000000000000000000</Binary>

  </EventData>

</Event>

Is this a hardware error in the Surface or the Card?

Several folks have had good reports about Samsung branded ones.

Excellent, as I have a new Samsung Evo+ 128GB coming from TigerDirect.