MIDI Connection Issues for a Yamaha PSR-400 (1991) : r/piano
Amazon.com: 12V AC DC Power Adapter for Yamaha PSR YPG YPT DGX DD EZ P Digital Piano Portable Keyboard Series (Replacement PA130 PA150, PSR-E403, Below YPT-400, Below EZ-200 EZ-AG) : Musical Instruments
Yamaha PSR-400: Midi signalled to death by Korg Triton - YouTube
Amazing!! Yamaha PSR-EW400 Keyboard - Quick Overview & Demo From UK - YouTube