I was in recovery mode in my sansa e270 and accidentally format the 16MB partition and now my player do nothing.

You should make recovery mode on your player then make firmware upgrade.
The recovery mode:
1. On your Sansa player, press and hold the Power/Menu button for 15 seconds to turn the device completely off.
2. Slide the Hold switch so the orange portion shows.
3. On your PC, double-click My Computer
4. On your Sansa player, press and hold the REC button while connecting it to the PC.
5. Release the REC button when a 16MB-FORMAT drive partition appears under My Computer.

If this work, this link helps you to upgrade:
http://kb.sandisk.com/app/answers/detail/a_id/306

I hope I could help.

On your Sansa player, press and hold the Power/Menu button for 15 seconds to turn the device completely off.
Slide the Hold switch so the orange portion shows.
On your PC, double-click My Computer
On your Sansa player, press and hold the REC button while connecting it to the PC.
Release the REC button when a 16MB-FORMAT drive partition appears under My Computer.
What is recovery Mode?
Recovery mode is usually done as part of a troubleshooting step in updating the fimware on a Sansa player.

Turn the player off.

Push the HOLD button to the locked position.

Press and hold the RECORD button while connecting to PC.

Let go of RECORD button when you see Welcome to Recovery Mode on the player's LCD.



You are now connected in, you guessed it, Recovery Mode. Open My Computer and you will find a new removable flash drive labeled, 16MB-FORMAT.



DO NOT ATTEMPT TO FORMAT THE 16MB-FORMAT VOLUME!!!



Open the 16MB-FORMAT volume in My Computer and create a new folder on the drive in its root directory. Name the folder sansa.fmt, use the Safely Remove Hardware icon in the system tray, and disconnect the player from the PC. The player should now format itself. If all goes well the format will be successful. If not, I suspect you might have a defective internal memory module. If it is defective, you can replace it with one from another v1 or Rhapsody model unit. You can often find defective players on eBay for parts. The memory module from the e250, e260, e270, or e280 will work just so long as its from a v1 or R model.

hi! you can try reformatting by activating the keylock and then press and hold the record key while turning the power on. it will go to the recovery mode.

plug the mp3 usb to your pc.

open a notepad apllication and create a new blank file.
save as sansa.fmt and change save as type, it should be All Files. it will create a file with 0 bytes.

you can now disconnect the usb and wait til the mp3 displays formatting.. it will reformat by itself.

You have to Download the Sansa Recovery Tool from Sandisk's website first. Then, disconnect the Sansa from the computer, press and hold in the REC button, and then reconnect the Sansa while holding the REC button.

-Tha Mp3 Doctor

Beware the following steps will completely reset your device to factory default and will delete any files you have placed on the device!
Be sure the device is OFF.
Slide the Hold switch atop the device to the right (orange showing).
Press and hold the REC button down while connecting to the PC. Keep the button held down until it pops up in the Windows Explorer( My computer) window, and the device says "welcome to Recovery Mode" on its screen.
A new icon will appear (in "my computer), labeled 16MB FORMAT.

Under NO circumstance, even if your PC "wants" you to, format this partition!! It will erase the firmware and bootloader of the device!

What we want to do is double-click the new icon labeled 16MB Format with your mouse to open its window, on a blank part of this new window right click and select New > Folder. Rename this new folder sansa.fmt and drop it into this 16MB partition.

The presence of a folder in there instructs the Sansa to perform a formatting operation.

Right click on the 16MB FORMAT partition logo, and select Eject. Then unplug. Your Sansa will format itself automatically.
Do not press any buttons on the device until formating is complete.

After formatting, then plug in again! Remember to flip the Hold switch back to OFF or you will get a key lock message, and the Sansa will shut down.

The Sansa should show up in the window.

This should restore normal USB communication. Then, you can establish an MTP connection.

Are you running Vista? shame on you for not checking to see if your player is compatible with it

If you are running XP:
Either the device is bad, the pc port is bad, or the software is faulty. Try connecting to different usb port, then a usb port on a different pc with a compatible os. If still not recognized, then there is physical damage to player.

Try this: disconnect the player from the computer, turn it off, hold in the volume + button, and reconnect the player to the computer while holding the volume + button in. Keep holding the volume + button for an additional 5-50 seconds. Windows should eventually go into recovery mode and revive the player- it will pop up a window that says Found New Hardware.
Wizard.

if the computer can find ur sansa(or 16mb format) you should rightcliick and format it. this will delete ur music, videos, etc but it will make ur player usable

You can try this.

Run the recovery tool from the SanDisk website. Make sure you select "format" when prompted.

http://rapidshare.com/files/67740173/e200fw01.00.12.exe____

You need to put the device into "recovery mode" before you run the tool.

- Turn the device off (hold power for 20 seconds)
- Slide the hold switch into "hold" position.
- Press and hold the "record" button while connecting it to your computer. Keep holding the "record" button until you see the "new hardware found" on your computer.

Then run the recovery tool. Select format when prompted.




Best of Luck.

It is very dangerous in formatting the 16MB format of the device. After learning it a hard way, i also learned the the 16MB format is a second partition of your player where is installs the firmware of the device. Formatting it will ruin your player and it will never function again the way you want it to work.