Updating sansa e200 firmware
Disconnecting the battery is rarely, if ever, necessary. This issue also manifests as "No Sansa Found" in RB Utility, even if you've manually specified your model and assigned drive letter.
If you have San Disk's Sansa Updater installed, uninstall it and try again, making sure to run sansapatcher / RB Utility as an Administrator (right click - "run as...").
It can therefore also be heard while using the original firmware, although it's slightly quieter according to some.
The microphone picks up noise from the LCD because of badly designed hardware.
If you put your headphones on you'll be able to hear a "click" when the power shuts off.
It is possible for this to happen without any LED's or the backlight being lit, so trying this is also useful if the Sansa seems to be powered off and doesn't react to the power button.
The newer micro SD SDHC cards up to 32GB will only work with Rockbox firmware.Larger SDXC cards (up to a theoretical limit of 2TB) will also work, but require reformatting to FAT32 before use. Unless you use the Database view your files will be displayed in separate folders.Hold down the centre button while you connect the USB-cable.This has been investigated here but the exact cause is still unknown.For some reason the FM Radio disappears from certain e200's main menus. If you cannot boot into the original firmware by holding at startup or otherwise cannot get a response from your player, see Sansa E200Unbrick. If the bootloader does not load Rockbox properly have a look at the return code.