Yamaha Keyboard P-95, no sound

Thread Starter

dontknowhow

Joined Jan 30, 2022
1
Hi all...

Same story, my friend gave me a P-95 with no sound. After reading this forum, I decided to take it and ordered the 16V 100uF capacitors online.

Before desoldering, I checked the caps inside the circuit, and indeed C216 is open circuit (shows "OL" on my meter).

With a bunch of spare caps, I decided that I changed all the same value caps: C216, C217, C404, C408 and C112.

Close back everything, powered ON, wow the beast is alive!!!

Happiness is shortlive, it was alive like 1-2min, while excitedly playing, I heard a faint *pop* sound. Then there's no more sound. The power LED is still lighted, but there's no more sound.

I opened up to inspect, there's no burn marks, the caps all still looks good. I measured C216, C217, C404, C408 and C112 again, they have some values, not "OL".

I'm an electrical person, but not very expert in it.

I don't have spare parts on hand, will need to order. looked through the other caps, the remaining ones on the board are:
- 50V 10uF
- 50V 4.7uF
- 16V 33uF
- 25V 47uF

So should I also replace the remaining other caps? I'm on the verge of throwing this to the trash.

Thanks for any advice..

Moderator edit: New thread created from this.
 

MrChips

Joined Oct 2, 2009
26,133
No. don't throw it out.
I am not a fan of replacing capacitors willy-nilly. I try to trouble shoot by functionality.
If you are willing to spend some time and effort we can trouble shoot the keyboard and try to find what's wrong.
 

dl324

Joined Mar 30, 2015
14,480
Welcome to AAC!
I measured C216, C217, C404, C408 and C112 again, they have some values, not "OL".
If you measured them in-circuit, the measurements are meaningless. Only a short would be significant. The final failure mode is usually open circuit (which could have precipitated from an initial short circuit condition).
 
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