nick,I was wondering if it is possible that your batteries are the part that stops your Roomba from working. Try to run the self diagnostics. Here is link [http://mysite.verizon.net/gsplews/Diagnositic-Tests_Proc.v.0.5.htm|link] to a really good site that will show you how to run diagnostics on your Roomba. It should help you to narrow your error down. Also check this [http://www.robotreviews.com/chat/viewtopic.php?f=1&t=14673|link] for more info (you are not alone with that problem:-) download the [http://myroomba.ru/download/roomba_400_series_service_manual.pdf|service manual from here.] Make sure you save it, apparently iRobot does not like us to look at their manuals :-) Good Luck