When the motor detects excessive force, it automatically shuts off and displays a 'JAM' error code. Jamming may occur due to: Incorrect feeding of bills into the 8800R V2 Bills with foreign objects like clips Worn, torn, soft, or folded bills that crumple Crooked entry of bills Improperly installed bill guides Incorrect feed gap adjustment; if too wide, it may accept multiple notes at once, causing frequent jams. For feed gap adjustment instructions, please refer to the PDF below. 8800R V2 Feed Gap Adjustment Procedure