Hi @laurelle ,
This is from the Oral-B website
The two-minute timer on our Oral-B Vitality toothbrushes should reset if the toothbrush has been switched off for 30 seconds. If you switch it off before the 2 minutes are up, and then switch it back on within 30 seconds, it will resume from where you left off.
If it does not perform this way it may be faulty.
There is a 2 year warranty on the product (may be country dependent - check in your location).
Contact Braun service, regarding replacements.