Thanks for that my WK4 was relegated to the Attic thinking it was broke, till I managed to track down the os for it most of the disks I had with styles went missing. Anyhow it's working again apart from the backlight gone on the display. Might be the inverter.
Gem Wk4, Solton Ms60, Technics Kn5000, Korg Pa50sd, Yamaha Psr k1, Tyros 4, Korg Pa700