TD
The captain of the aircraft signs to accept the jet after the whole crew have completed there pre flight checks. They would bring his attention to any malfunction they encountered. It is then up to him to sign as accepting the aircraft. Before this the Before Flight servicing will have been carried out by the ground crew and a dispatch check by the crew chief. Any faults found during this stage would probably stop the crew from even getting to the aircraft, the crew chief will not allow the crew to start their pre flight until he is satisfied the aircraft is servicable, we could of course be carrying unservicable items but these would have to be detailed in the F700 and be deemed safe to fly iaw the servicing manuals. The captain retains the right to refuse an aircraft at any time. So you can see it is a team effort and anyone can flag up problems at any time.