I used my sparkfun bluetooth module in normal operation under 5V and it suddenly stopped working. The LEDs don't turn on any more, although voltage to the device correctly is measuring at 5V. I assume it fried.
It supposedly can't go above 6V supply voltage according to the datasheet, although a few weeks ago I gave it an unregulated ~6.3V by accident and it worked fine. I long ago realized the mistake and had it already back under 5V before it actually fried . . .
I doubt anyone knows how to revive it, so just posting this for the possible benefit of others . . .
btw, I'm using an older version than what Sparkfun currently sells. This is the newer version:http://www.sparkfun.com/commerce/product_info.php?products_id=158
The newer version has a few additional components and slight rearranging of the others.
I don't remember when I bought it, but I do know it was before April 2008.
edit: reworded this a bit, living in Thailand too long is making my english all funky . . .