The PSR3000/2100/2000/1500/1100/1000 power supplly, the PA300, is unique. You are risking frying out your keyboard if you try anything else.

You must have a backup anyway. My power supply just failed me after ten months of twice daily use. I'm using my brand new backup. In a couple of weeks I'm going to order another one. They're expensive, but indispensable.

Beakybird