I have a Clavinova I purchased approximately 6 years ago and it is driving me crazy!! It keeps shutting off in the middle of playing, and it takes forever to turn on. I literally have to turn it "on" and let it warm up for an hour or two before I can even play the thing, and then it will shut off randomly throughout my playing (and by randomly I mean sometimes every 2 seconds and it won't stay on longer than 10 minutes)

I bought it in Japan but I'm pretty sure it's an American model. I never had a problem with it until I moved back to the US. I've changed cord. I've changed where it was plugged in. I am very careful about different voltages in various countries so I know that its currently on the right setting and always was.

Does this sound like a problem that is fixable or should I just dish out some money for a new one? Would the repair be expensive?

Does it have an external transformer/power-supply block where you plug one end to the power outlet in the wall, and the other end (a DC output) to the Clavinova? If yes, I'd try to look for a replacement for this first to see if it'd help. It sounds like a power supply problem. If the power supply gets flaky on you, any time it cannot supply the current demand required, the voltage would drop and cause the Clavinova to turn off. If your power supply is external, then it's simpler to try to find a replacement. If it's internal, the repair is a little more involved, but I don't think it'd be terribly expensive to replace a power supply.

It probably is a power supply issue. The power supply is internal but there is an external plug that connects the piano to the outlet which I have already switched out with no changes (it's a standard size so I've been able to get the same type of plug from a laptop and stereo with no change in performance).

Yes it might be a power supply issue. When they shut down but are not broken it maybe that it is do to some safety shut down circuit. Like over temperature or over current.

Power amplifier can act the same way, THey will shut down if they get to hot or over current too. DO you know if the power is shutting off or is it just the sound that goes off?

Over temperature might happen if there were a heat sink and the cooling fins got packed with dust. Over current can happen if there is some kind of parts failure.

Can you open the case and look?

My non technical guess is this, the piano wants to see 100 VAC either 50 or 60 cycle and you're giving it 115 VAC 60 cycle. (Half of Japan is 100 VAC 50 cycle and the other half is 100 VAC 60 cycle.)

Apart from that, I'd give Yamaha a call and have a tech give it a look.

One time I lost an external power supply to one of my Yamaha portable keyboard and I tried to use a different power supply with the same plug size and dc output voltage, although a lower current rating. So my Yamaha would still turn on and work, but if I turn up the volume louder, it would turn off by itself. I think this is because my alternate power supply was under-power for the power requirement of the keyboard. So if your power supply is getting old and can't deliver the same power as before, and is borderline in delivering barely enough power to your Clavinova, the Clavinova may work for a while but shut off when conditions demand more power than the power supply can deliver.

Volusiano: The power supply in a Clav is internal. There's nothing the OP could have done to alter it or replace it.

Dave Horne: Interesting point about the 100 VAC in Japan. I always thought Japan followed American standards quite closely, but I guess this is one place where they differ. It's quite possible that 120 VAC in the US is causing a problem.

Ender Wiggin: I think your best option is to have a shop look at the piano. But there is one possible (and cheap) test that you could run (maybe).

First, check to see if Dave Horne is right. Is your piano meant to run on 100 VAC? The label underneath the keyboard might tell you. It will have make, model, serial number ... and maybe the correct power requirements.

If it really does want 100 V instead of our standard 120 V, then ...

Maybe you can find someone who has an auto-transformer (or variac). It's an adjustable transformer that plugs into a normal outlet. The piano would plug into the outlet on the transformer. The auto-transformer is adjustable. You can dial the voltage to any setting, from 0 to 120 V. If you dial it down to 100 VAC, maybe the piano will be happy and run without problems.

If not, then something else is wrong.
But if this works, then:
1. Find out if Yamaha can swap out the piano power supply for one that works on 120 V. It might even be fixable without changing the power supply ... there might be a switch or jumper setting that can be changed to make it right.
2. Buy an auto-transformer. They're not cheap, though. A web search turned up units that cost $150 and up.

Some might find this interesting ... Electricity around the world

You might try getting help from Yamaha.
In the US:
Phone number: 714-522-9000, Monday–Friday, 8:30 AM – 5:00 PM Pacific Time.
Online request: http://www.yamaha.com/yamahavgn/CDA/ContentDetail/WrappedTextDetail.html?CNTID=544117

Thanks for all the suggestions. I have lived in other places besides Japan with my Clavinova and i have a feeling that those other places are what ruined my Clavinova. In Japan/US the electricity is clean, but other, less developed, countries are not. Power surges and power outages were quite frequent.

My yamaha has an adjustable voltage/transformer built into it (is this standard?) and that's what I've used to switch between countries no problem. i'm scared to adjust it though...in the past if I stuck an electronic device in the wrong voltage it would start smoking, blow up, which is not what I want.

I don't know how to open the case..I will try calling Yamaha.

A Yamaha tech recently opened the top of a cvp-505. It is held by two +head screws hidden under the front corner of the top just above the keyboard lid, an excellent location for a clean look. The top was then removed by sliding it an inch forward and up. Inside is neat and almost empty : power supply, mainboard, amplifier, interface board and the 88-key assembly. CVP-505 big speakers are in another box under the main body.

I would suggest a full factory reset to removed any possible problem with the O/S. Press a C#Maj chord below middle C (C#2 + F2 + G#2) and turn ON the power. Use the Tempo +/- to scroll down the Test Diagnostic options to Factory Reset. Enter Start/Stop to select. You exit this mode simply by power OFF. But use this with caution as the unit need to be fully powered when performing the reset operation.