I've recently flashed the stock firmware onto my Samsung Galaxy S3 because there was one feature which didn't work on CyanogenMod. My external SD card worked fine until recently - the 'mount SD card' option in Settings is now grayed out, and whenever I insert the SD card into the device, the following messages appear in the logcat:

W/MountService( 3370): Failed to mount media on insertion
W/MountService( 3370): java.lang.NullPointerException
W/MountService( 3370):     at com.android.server.MountService.doMountVolume(MountService.java:1212)
W/MountService( 3370):     at com.android.server.MountService.doMountVolume(MountService.java:1288)
W/MountService( 3370):     at com.android.server.MountService.access$2100(MountService.java:134)
W/MountService( 3370):     at com.android.server.MountService$6.run(MountService.java:1021)

My computer seems to recognise the SD card just fine. Can anyone help me with solving this problem?

Update 1: I was successful in mounting the SD card manually using the shell command from this tutorial: http://forum.xda-developers.com/showthread.php?t=1804573, however it was only accessible to apps with root permissions.

Update 2: As suggested in the comments section, I formatted the card in question to exFAT. The problem persists.

Update 3: The dmesg (/proc/kmsg) file seemed to have some relevant information. This is what got logged into it when I removed then inserted the card:

<6>[ 5096.384848] c2 mmc1: card removed.
<6>[ 5096.385093] c0 mmc1: card e624 removed
<6>[ 5096.478613] c0 sdhci_set_ios : MMC Card OFF samsung-hsmmc
<6>[ 5097.221780] c2 mmc1: card removed.
<6>[ 5097.221830] c2 mmc1: card inserted.
<6>[ 5097.421722] c2 sdhci_set_ios : MMC Card ON samsung-hsmmc
<6>[ 5097.450386] c0 mmc1: cmd 52 command timeout error
<6>[ 5097.450735] c0 mmc1: cmd 52 command timeout error
<6>[ 5097.454610] c0 mmc1: cmd 5 command timeout error
<6>[ 5097.454944] c0 mmc1: cmd 5 command timeout error
<6>[ 5097.455274] c0 mmc1: cmd 5 command timeout error
<6>[ 5097.455606] c0 mmc1: cmd 5 command timeout error
<6>[ 5097.599241] c2 mmc1: new high speed SDHC card at address e624
<6>[ 5097.600105] c3 mmcblk1: mmc1:e624 SU32G 29.7 GiB
<6>[ 5097.614116] c3  mmcblk1: p1
  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Andrew T.
    Jul 30, 2022 at 16:22

1 Answer 1


I fixed the problem just by flashing the stock firmware (using Odin) again. I didn't even have to wipe /data - all my apps are still there.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .