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Rusty, Music Professional
Category: Electronic Musical Instruments
Satisfied Customers: 6059
Experience:  Sound Engineer, Electrical Issues, Tone Consulting
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I have just repaired the keybed on my Yamaha cp300 (sticky

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Hi I have just repaired the keybed on my Yamaha cp300 (sticky keys), I plugged everything back in as was, but now the keys are not being read. The Unit works ok in demo mode, all the switches work, but there is no output from the keybed - any suggestions?
Hello, my name is Rusty. The tone generator is the first in line as far as signal path. It goes from the tone generator to the pitch bender. The pitch bender stores all percussion, and the demo songs. Then the signal gets sent to the amplifier.
Since the demo is working, you have a break in continuity from the tone generator to the pitch bender/mixer.
Check for a loose power wire on the tone generator, or a deteriorated ribbon from the keys to the tone generator. Tell me what you find.
Customer: replied 3 years ago.

Hi Rusty,

Thanks for your help. I've checked all the wiring, everything looks pristine (this was the first time it had ever been opened). All the plugs and sockets in the path from the keybed to the first board marked DM and from there to the left hand front panel card marked PNL look fine, no bent pins or loose wires. I'm guessing that I'm going to have to get the multimeter out and start checking continuity in the wiring harness. I was hoping that this was a stock fault that had been seen before.


While it's open, use some compressed air to clean the keys. This is a good time to do it, since it's already open. There is one more thing to check...
In your midi settings, set local control to on. If it is on, and still won't produce sound, test for power at the tone generator, and tell me the results.
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