Yamaha Clavinova CVP 98

Synth Repair
1

Hi,

Hoping someone might be able to help me with an issue on a Yamaha Clavinova CVP 98.

Within about 5-10 minutes of playing, the piano makes an extremely loud popping noise followed by a distortion like sound. An engineer has been out to look at this and advised it could be a problem with the main board and has said it’s not a power fault. The noise is very alarming and catches you off-guard so unfortunately it’s unplayable at the moment. As the piano holds a lot of sentimental value, would like to find out what our options are to get this fixed but struggling to find anyone who can advise or actually do a repair.

Any help would be appreciated.

Thanks in advance.

James

2

Has your tech been running diagnostics?!
Can you follow these instructions and run diagnostics on RAM,ROM,WAVE ROM etc etc and let me know what you get.

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3

Hi,

Thanks for responding. Ran all the tests and all have come back OK.

I’m not sure what tests the engineer ran but he did actually take the board away to see if he could fix it to no avail.

Thanks

4

Does the CVP-98 do same when running the DEMO songs?

5

Yes in fact it makes the noise randomly even when nothing is being played

6

Also happens through headphones so not a speaker issue

7

Does it stop with Volume down to 0?

8

Yes it does, piano was turned on for 7 minutes before the noise happened and when you turn the volume down, the noise reduces. Leaving the volume off completely, can’t hear the noise

9

Two more things:

  1. Does the noise happen in both speakers (left and right) - if so that would exclude the DACs since there are two - one for each side.

  2. Has a full factory reset been done? If not, or if you are unaware, run test mode again as per previous instructions and then run Test 47 (Factory Reset) - wait for it to finish - do not turn off power whilst reset is running. Upon completion run Test 48 which will exit test mode

Now see if any change.

10

The noise does happen in both speakers yes, also happens through headphones.

Will give the factory reset a go and let you know if that changes anything. Thanks for your help so far

11

Factory reset didn’t make a difference unfortunately

12

I’m pretty sure this has to be an issue with a component(s) on the main board but Yamaha don’t make the boards for this anymore and I’m struggling to find anyone who could possibly look and repair

13

That is pretty much where we are now - all we done has excluded most if not all all components after the main CPU. Serial digital data leaves the CPU as two separate signals (L + R) straight into the DAC’s (Digital to Analog Converters) from where on the signals for left and right are separate - hence would assume that a fault like that would most probably not affect both signals at the same time. The fact that the unit works for a few minutes before going “silly” would suggest an electrolytic capacitor some where BUT also could be a temp related issue. My bet at this stage would be around a bad RAM chip.

You will have a hard time finding a board or even individual components - CVP-96/98 were released 1997 … so that is 26 years ago. YAMAHA guaranties spares ans support for warranty + 7 years which in this case would be 10 years.

Sorry can’t be of any help further than that :frowning:

14

OK well thanks very much for your help anyway, doesn’t look like there is much we can do

15

Hi Wernersaurus, I have the exact same symptoms from my CVP-98. I am about to replace the DACs and RAM chip if I can find the chips and someone with a steadier hand than me. I will drop an update here after I get the work done.

If this fails do you think there is any way to reuse the mechanical part of this keyboard. Please forgive my lack of knowledge, I’m just thinking outside the box here. I only use the piano and electric piano voices and absolutely no other features of the piano so my thought is to find a way to replace the motherboard with a more modern board and map the piano voice to the keys somehow. Is something like this even possible? Sentimental value and a current lack of cash is stopping me from buying a new piano.

Thanks for the feedback on this thread so far.