90 days and my SSD has failed?

So my desktop PC hung yesterday, and on reboot attempts, offers only "Media test failure. Check cables" or words to that effect. In the past, this ended up being either the END (or near the end) of whatever C-drive I happened to have installed - in fact, that's why last time, I bought and installed a SanDisk 120GB SSD a few months back to replace a possibly-failing WD90GB drive. So...what, here I am AGAIN?

I tried the MBR-restoration routine at MBR - Restore Windows 7 Master Boot Record - but I don't even see the SSD represented in the diskpart display (that's after booting with Win 7 DVD & getting a DOS window open.)

I also tried plugging the SSD into a spare external enclosure yesterday - at first, it would show up in Disk Manager and was showing the full file structure, but wouldn't let me copy or move anything - almost instantly would give me an "unrecoverable $Mft" type error for that drive letter.

Now it doesn't seem to even show up in Disk Manager.

Is this three-month-old SSD really toast? Why do I go through about a drive a year, when they're just sitting there on my desktop? If SSD's are to be trusted, then is there any good database on reliability/MTBF etc?

Try doing a power cycle of the SSD. The following steps should be carried out and take ~1 hour to complete.

1. Power off the system.
2. Remove all power supplies (ac adapter then battery for laptop, ac adapter for desktop)
3. Hold down the power button for 30 seconds to close the circuit and drain all components of power.
4. Reconnect all power supplies (battery then ac adapter for laptop, ac adapter for desktop)
5. Turn on the system and enter the BIOS (see your manual for the steps to enter the BIOS)
6. Let the computer remain in the BIOS for 20 minutes.
7. Follow steps 1-3 and physically remove the SSD from the system by disconnecting the cables for a desktop or disconnecting the drive from the junction for a laptop.
8. Leave the drive disconnected for 30 seconds to let all power drain from it.
9. Replace the drive connection(s) and then do steps 4-8 again.
10. Repeat steps 1-4.
11. Start your computer normally and run Windows.

The above steps were a result of: Why did my SSD "disappear" from my system? - Crucial Community

While that may not be your drive, a power cycle should be the same on all SSD drives. See how the system responds after the SSD power cycle.

Thanks for the replies.

The "power-cycle" process sounds absurd in the extreme (at least it doesn't involve dead cats or stump-water) but I will try almost anything if it's even marginally easier than another clean install on a warranty-replacement SSD - which seems to be where I am headed. SanDisk's new-firmware process didn't make any difference.

As for the chronic failures: If there's a problem with HD controller or even home power - what's the diagnostic used to check those possibilities? Just earlier this week my 1.5TB external came back from would-be drive recovery as "unrecoverable." The same PC (with previous mobo) had the factory C-drive fail under warranty when nearly new, though an aftermarket replacement HD I stuck in there seemed to do OK... other than chronically being tied up with pagefile-related processes, which was part of why I "upgraded" to this SSD.

Personally, I think there's an ancient Hawaiian burial site directly beneath my desktop.

A silly question... how old is your desktop's PSU?
Every time my computer starts showing signs of erratic operation or parts dying - hard drives, optical drives, mice, etc. - replacing the power supply fixes the problems. I've yet to get more than two and a half years out of a power supply.