Samsung SSD 830 disappears A Samsung SSD 830 installed on a MacBookPro 2011 with Mavericks 9.5 was chugging along nicely until a file save action generated the coloured beachball ... and nothing else was active. I initially assumed a system freeze...  

However, after pulling it out and attempting to connect as an external drive via USB to both its intended unit and another MBP with Snow Leopard, the disk is never recognized.

System logs are naturally unaccessible.

I've read around that it may be a firmware issue, however the info is sketchy. Samsung has a latest firmware FDOS OEM CD with a version of DOS and the Firmware Update Application for Mac users (really one can boot from a small DOS?).  However using DiskUtility and trying to copy btdsk.img or its parent Samsung_SSD_830[...]_Mac.iso to a USB disk DiskUtility asks for permission to scan the img file, but drops the destination USB unit (loop into empty...) and also returns (Invalid argument)

Many variables are now up in the air.


Is the SSD fried or really needs a firmware upgrade
I need pointing to a good ressource to make this supposedly DOS-booting drive for the firmware update.  ALternatively, is there a better way to achieve this? 
Will I lose the data on the SSD? (I was lulled into the comfort of quiet speed and have quite a bit of work not backed up.  Mea culpa)
It may be fried, although 4 years is much shorter than expected lifetime.
When it was "was chugging along nicely" until now, I think a FW update will not succeed, nor be the cause of this stroke. It may be too full also.
I suppose that you already tried to see it in the Recovery Partition (start with CMD+R) and "repair disk" it with DiskUtility.