This comprehensive repair manual provides you with all the necessary information to troubleshoot and repair your 1991 CASIO SA-21 Electronic Keyboard. It includes detailed, step-by-step instructions and visual diagrams, guiding you through every aspect of the repair process. Whether you're a seasoned technician or a DIY enthusiast, this manual will empower you to confidently address any issues your keyboard might be experiencing. The manual covers a wide range of topics, including diagnosing common problems, replacing components, adjusting settings, and understanding the keyboard's internal circuitry. Get the confidence you need to keep your CASIO SA-21 Electronic Keyboard in top working order with this detailed and informative repair manual.