BELL & HOWELL - bh projector 346a

Comprehensive service manual for technicians and workshop professionals covering the Bell & Howell Design 346A Autoload Super 8mm projector. This detailed technical guide addresses all aspects of projector maintenance, repair, and precision adjustment. The manual opens with an introduction to the automatic self-threading system principles, specifications of required special tools (both shop-made and commercially available), and recommended lubricants. The Disassembly Procedure section provides systematic step-by-step instructions for complete projector disassembly with specific precautions noted for each component. The Reassembly and Adjustment section details complete reassembly procedures combined with critical adjustments including reel spindle torque adjustment, threading mechanism setup, aperture plate and lens carrier alignment, safety shutter clearance adjustment, and picture framing lever positioning. A comprehensive troubleshooting chart addresses common operating problems including projector inoperability, picture flicker, film scratches, jumpy images, soft focus, autothreading failures, film spillage, and mechanical noise, with identified probable causes and specific remedies. The Final Test section covers inspection procedures, operation testing, safety shutter function verification, and optical alignment verification. Detailed exploded parts diagrams and complete parts lists accompany the text, covering lamp assemblies, reel arms and gears, loopformers and sprocket gears, shuttle mechanisms, and motor and base components, with part numbers and identification codes for all components.