This is great! Casio WK-3700 synth keyboard with DSP and ZPI processor - YouTube
CASIO WK-3700 SERVICE MANUAL Pdf Download | ManualsLib
AC Power Adapter for Casio WK-3700 LK-93TV CTK-481 CTK-483 CTK-491 Keyboard | eBay
User manual Casio WK-3700 (English - 132 pages)
Amazon.com: MaxLLTo 6ft Extra Long AC Power Replacement Adapter for Casio WK-110 WK-200 WK-210 WK-3700 Keyboard Charger Power Supply Cord : Musical Instruments