8 months ago, I installed a 250GB Crucial MX200 in my 7140. As soon as Windows 8.1 was running, I disabled Link Power Management. Yesterday, as part of an effort to fix the battery run-down-during-sleep problem, I re-enabled Link Power Management. This appears to have killed the drive - when I try to boot, I get "No bootable devices found", and when I boot from a USB recovery thumb drive, the MX200 is not visible from any of the recovery tools nor from the command prompt, even after repeated power cycles.
Btw, disabling Link Power Management didn't fix the battery run-down-during-sleep problem for me. After disabling Link Power Management, I put the 7140 to sleep, with about 95% battery remaining. 6 hrs later, I tried to wake it up, and the battery was completely drained, and the drive was dead.
I've just placed an order for the Transcend MTS600 256GB. Hopefully, it will do better than the Crucial.
There exists scheduled jobs which can wake a sleeping tablet. Check your System events log for "Kernel-Power" Event ID's 42 (sleep) and 131 (resume) for this action.
To the point, you might want to try the old remove, clean contacts
and replace SSD drive just to make sure it is firmly in place...
I just removed the Crucial MX200 and replaced it with a 256GB Transcend MTS600. While I had the tablet open, I re-seated the Crucial drive, as you suggested, and tried to boot it, but it didn't help. The Crucial drive was running the latest firmware (MU03).
I've installed a daily build of Ubuntu 16.04 on the Transcend drive, to see if it might do better than Windows 8.1, which has major problems with power management and sleeping on this tablet.
I've been running the latest daily build of Ubuntu 16.04 (which is still in beta testing) for a couple of days, and its sleep behavior isn't any better than Windows. The only usable sleep mode is hibernate.
The Transcend drive is working fine, so far.