BELL & HOWELL - bh projector 1620 23

Comprehensive service manual for Bell & Howell automatic film projectors compatible with standard 8MM and Super 8MM film formats, covering Design 1620 and 1623 models. Features detailed step-by-step disassembly procedures organized by major assemblies: gear train operation, film guides, main plate components, mechanism module, and aperture plate assembly. Reassembly and adjustment sections provide precise instructions for reconstruction, including module gear timing diagrams, spring tension balancing, and aperture framing alignment. A dedicated final test section covers mechanical inspection procedures, general operating tests, and critical frame positioning checks necessary to verify successful repairs. Extensive troubleshooting guide addresses common issues including picture flicker, film scratches, soft focus, jumpy picture, and film transport failures with specific remedies for each problem. Includes detailed exploded-view parts catalogs with component identification and part numbers for all assemblies. Special maintenance precautions and required service tools are clearly documented. Supplementary data for Design 1625B model provides additional design variations and electrical wiring diagrams for room lamp receptacle installation. All specifications and procedures applicable to both 1620 and 1623 designs with clear notation of model-specific differences.