Norma Spreeman, start off by resetting your Roomba
1) Turn Roomba over on its back
2) remove battery
3) turn Roomba back over
4) press and hold power button for 5 seconds (no lights will)
5) Turn Roomba over on its back
6) Reinstall battery
7) Allow Roomba to recharge for 16 hours uninterrupted (even if power lights indicate it's charged sooner)
The service manual is available [http://myroomba.ru/download/roomba_400_series_service_manual.pdf|here.] Here is a great [http://mysite.verizon.net/gsplews/Diagnositic-Tests_Proc.v.0.5.htm|site] that will show you how to perform diagnostic tests on your Roomba. Hope this helps. Good Luck.