I risked it and ordered one from ebay..
http://cgi.ebay.com/ws/eBayISAPI.dll...LLBUY.m311.lVI
$20US including shipping. The picture shows it as a Dell part and the seller seems to have solid feedback. I will cross my fingers.
I am surprised the little $hit (puppy) didn't zap herself or blow some breakers. It was plugged in when she decided to gnaw away at it.