Yamaha Keyboard P-95 repair

JoeJester

Joined Apr 26, 2005
4,390
Shorted is not the condition causing the fault.

You need something to test ESR and capacitance ...

The other option is if your not interested in troubleshooting, you can replace the one's you haven't replaced. If you are interested in troubleshooting the problem, you'll need more than the meter.

You can get a multifunction tester ... not a professional one, for really cheap that can give you some indications of out of specifications.

From the problem description you have, it would be better if you had some type of oscilloscope and something to check the ESR and value of the capacitance.

What part of the world are you located?
 

Thread Starter

lby0001

Joined Jan 12, 2020
11
It might be a cap that's failing (high ESR and/or lower capacitance) on the power supply. You can troubleshoot by putting a good cap across any caps that you suspect. Make sure you don't short anything. I'd use a couple test clips.

If you do this, check the voltage rating on the suspect cap so you have an idea of the voltages you're working with. It goes without saying that the good cap should have the same or higher voltage rating. Also don't make it huge compared to the original.
By across existing caps, you mean in parallel?
 

JoeJester

Joined Apr 26, 2005
4,390
yes he means in parallel.

If they are all connected to ground, and from what I saw of the schematic, they are. you can connect the negative to ground and just touch the positive side of the capacitors with the non-grounded lead while you have the noise to see which one reduces it.
 
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