Bobby goes to buy a cd player from sammy's electronics. in testing one model, bobby notices that the "scan" function does not allow scanning once a selection from a cd is playing. bobby purchases the model despite this without mentioning the defect to sammy. bobby takes the cd player to his office where he uses it for three months before deciding that he wants to return it. under these circumstances:

I would say that Bobby once he has used the CD player for 3 months without a complaint he may not be able to return it. Only if there is a 3 month warranty, then he may be able to return it/replace it or if he has an extended warranty, otherwise he is probably out of luck.

Under these conditions, Bobby has accepted the CD player, because it was the buyer's (Bobby's) responsibility to inform the seller (Sammy) about the defect. Since he bought it regardless and used it for quite some time despite having to face the defect for quite some time, it fully belongs to him. In other words, he has already accepted the CD player and can't ask for a return of funds from Sammy Electronics.