Sansa Fuze- 'FAT is corrupted. Please connect device to PC and recover FAT.'

It sounds like your firmware update got interrupted partway through and scrambled the Fuze’s tiny brain.

Uninstall the Updater from your computer. There won’t be any more updates. Then update manually.

Go to the firmware link and download the two firmwares (1.x and 2.x) from the All Regions links.

http://forums.sandisk.com/t5/Fuze/Sansa-Fuze-Firmware-Update-01-02-31-amp-02-03-33/td-p/139175

Unzip them–you’ll find two folders with fuzeA.bin inside. Name the folders  so you know which is v1.xx.xx and which is v2.xx.xx 

http://forums.sandisk.com/t5/Fuze/Sansa-Fuze-Firmware-Update-01-02-31-amp-02-03-33/td-p/139175

It’s essential to get the Fuze connected. The way that works most forcefully is:

Hold the power switch up for 15-30 seconds, long after it goes black.

Slide the power switch down to click into Hold position. You’ll see an orange dot in the slot.

Connect the USB cord to the computer. Open Windows Explorer (Computer).

Hold the << and connect the Fuze. With luck the two drives will pop up.

Look inside the Sansa Fuze drive for version.txt.  That should tell you whether you have version 1.x or 2.x . They apply to two different pieces of hardware–2 is not an upgrade of 1.

Drag the appropriate FuzeA.bin over to the SansaFuze drive, just drop it right onto the driveletter.

Unplug and your firmware should upgrade.

If you can’t connect, try a different USB port on your computer–back ones are better on laptops. Or try a replacement cord (under $5 for a generic at Amazon or from cellphone accessories sellers–make sure it is for Fuze or Sansa E200–NOT AN IPOD CORD).

You can’t do it without a connection, so if it’s impossible to connect say goodbye to the Fuze.