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I have a 28 year old Disklavier C7 MKII with a DKC-850 Controller. I can get around connecting it via the Original DKC100R control unit, by using the converter board made by Richie Hayes.
Anyway, recently the piano has started to spontaneously switch itself off. First, it was after 10 or so minutes-but now it is within a few seconds of turning on the control unit.
It was doing the same thing about a year ago, but for some reason the problem went away - but has now suddenly reappeared.
Has anyone experienced this kind of problem? Does it sound like a power supply issue? The power unit was replaced about 10 years ago...
Switch off could possibly be linked to a power supply issue. In many cases, capacitors that have gone out of specs due to aging or damage -- can result in issues. Or, if the power supply has components overheating - such as if it has a fan that has failed. Although, for electronic music instruments, I assume the supply has no fan. If the circuit board can be inspected - in the power supply area --- can look for cylindrical capacitors with 'bulging' tops, which would be sure signs of issue. But - capacitors that no longer have their specified capacitance can sometimes 'look' perfect on the outside.
I have a 28 year old Disklavier C7 MKII with a DKC-850 Controller. I can get around connecting it via the Original DKC100R control unit, by using the converter board made by Richie Hayes.
Anyway, recently the piano has started to spontaneously switch itself off. First, it was after 10 or so minutes-but now it is within a few seconds of turning on the control unit.
It was doing the same thing about a year ago, but for some reason the problem went away - but has now suddenly reappeared.
Has anyone experienced this kind of problem? Does it sound like a power supply issue? The power unit was replaced about 10 years ago...
Cheers.
I hope you find an answer to this! There's so little information about the Disklavier available online that owners are often left to their own devices. If you know Richie Hayes, then you may have also run into TAP Electronics, who can repair Disklavier power supplies, and potentially help with other issues:
Personally, I'd love to see Yamaha commit to ensuring (paid) replacement/supply availability for 25-30 years for Disklavier, given how long-lived the pianos these electronics are attached to are. Would be nice if they provided service manuals for legacy models, too.
Thanks for your responses. Just an update on things.
I ended up going back to the old configuration with just the original DKC100R controller connected to the piano. It doesn't have its own power supply so relies on power coming from the piano. So when I fire it up, the piano and controller turn on (with red lights visible inside the piano so I know its all actually powering up) However, after 3 seconds it all switches off and goes dark - and the controller loses power.
If as suggested, it was a capacitor, would the piano power up in the first place? It seems like it can actually run power to where it needs- but something is overriding it to turn it off.
Is there a way to run a diagnostic test or something on a MKii?
I don't know that we can answer for sure. There are possibly many failure modes even for a power supply. Eg a cap that is falling but not yet completely blown out, might run long enough for the initial POST but then v after 3 seconds something else starts to power on that terriers additional power and that's when it can go longer supply enough. Or it could be thatv the something else is what is failing, and causing the entire system to shut down...
Does the power supply look anything like in this relatively poor picture quality video?
Just got to be careful with power supplies (in case some people don't know it) - as in - be really careful to not touch heat-sinks or anything, as some heat-sinks can be either at AC mains voltage or even higher --- potentially dangerous (aka potentially deadly). That's if there are heat-sinks in there.
The weird 'electronic' sounds in the video are weird hehe. But at least we can see a power supply sometimes (when the white card isn't blocking our view that is).
The bigger capacitors with the brown colour can certainly get out of specs over the years. And those ones can look 'perfect' on the outside, but can be out of specs. It's actually hard to say whether one or more of those capacitors have gone out of specs or not - unless each ones is removed and measured (with a suitable capacitance measuring device).
