Power supply failure in older DKV's is a common problem. If it won't turn on the first thing you should check is, is it plugged it? Followed by, is it plugged in to a switched outlet? Also, is the power supply actually turned on? If the power supply is off, turning it on from the control unit won't do anything.
OK, so now we have confirmed that the power supply is dead. The ONLY place that Yamaha currently recommends is called TAP Electronics, in Buena Park. ( 714-562-7400 ). You won't like dealing with them but they are experts and, like I said, your only choice. You will need to remove it from the piano, actually quite easy, and send it to TAP. TAP will rebuild it and send it back to you at what I consider too high a price. Yamaha has the plugs configured so that it's pretty much impossible to hook it up again incorrectly. I recommend you give TAP a call, giving them the model of the DKV itself, which is not the same as the piano, and asking if this is still a serviceable item. The DKV model is clearly displayed on the front of the control unit under the keys on the right side of the piano.
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Geoff Sykes, RPT
Los Angeles CA
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