This paper proposes an automatic defect detection system utilizing a YOLO-based deep learning model to address the time-consuming and labor-intensive task of industrial manufacturing. Using a metal plate image dataset, we train a YOLO model to detect defects on the surface and holes of the metal plate. To address data shortage, we used ConSinGAN to generate data and augmented it with four YOLO models: YOLOv3, v4, v7, and v9. The proposed YOLOv9 model, combined with ConSinGAN, outperformed other YOLO models (91.3% accuracy, 146 ms detection time). It was integrated into manufacturing hardware and SCADA systems to build a practical automated optical inspection (AOI) system. Furthermore, the proposed automatic defect detection method can be easily applied to other components in industrial manufacturing.