A family member recently gave us an RD-700 in excellent condition, but they couldn't find the cables, so I need to replace them. I read in one place that it needs both a power cord and also a power supply. However, the owner's manual says nothing about an external power supply, nor do I see any place to plug one in; only the plug for the power cord. I don't know much about these things (maybe that's obvious), and I've been unable to find the answer on the internet or by calling Roland dealers or even (amazingly) an authorized Roland repair center. It seems like a simple question. Can anyone tell me the answer? Thanks!