Finally, some ballots may be rejected entirely by the DS200.
The most common situation is a mismarked ballot. This is when a voter has made erroneous marks outside the ovals which prevent the scanner from properly reading their selections. In this case, the DS200 will return the ballot, make a loud beeping sound, and display an error screen.
If this happens, ask the voter to first turn the ballot over and insert it again. If it continues to happen, stay at the machine and call the Chief or Assistant Chief. They will review the situation and likely help the voter SPOIL the ballot and issue them a new ballot.