Yamaha Keyboard. I have a Yamaha SY77 keyboard, which has a 720k floppy drive built in.

Question

I have a Yamaha SY77 keyboard, which has a 720k floppy drive built in. Unfortunately it's not working, so wanted to replace it. Can I use a 1.4mb drive instead? If so, how do I overcome the difference in the power connection type between the drives? (the 1.4 mb has a 4-pin power connector). Or does anyone know where I can obtain a replacement 720k floppy drive?