Hey,Hello everyone,
I have a Yamaha P-95 that after approximately one year of being stored, currently is not emmiting any sound from either speakers or headphone plugs.
I checked the functionality of the Keyboard and the MIDI processing was ok. I tried all the quick solutions out there (enabling internal audio, check if something is blocking the headphone plugs, cleaned volume key), I figured it had to be the amp board so I decided to open it and see if there was a component with blackened leads, or some visual clue of the problem, but unluckily the problem wasn't so evident and there were no faulty components to be seen.
Looking for schematics I came across a post in this forum that stated a similar problem:
https://forum.allaboutcircuits.com/threads/speaker-relay-on-yamaha-r-90-receiver-not-closing.77234/
In wich it states that the keyboard has a protection circuitry that closes the speaker feed relay if after a few seconds from turning on the output stage is found healthy. This is indeed the case as I can hear the relay closing, and even opening again each time I connect headphones on either plug.
The strange part is that, trying to troubleshoot the situation, I unplugged the headphones board and after reconnecting it, the problem went away... unitl I turned the keyboard off and on.
Sadly the service manual has no schematics of any board. It only shows the disassembly of the unit.
Any thoughts on what may be the problem?
Thanks for reading,
German.
This fixed it so awesomeHey,
just bought a P95 with the very same Diagnosis. No sound, but Midi was working. I exchanged C216 + C217 then checked them with my Multimeter, they had been okay. Then exchanged C112 also. Bam! This one was broken. You couldn't see it from the outside. P95 working fine again. Thanks a lot!!!
Walt
The normal failure mode for electrolytic caps is open (an initial short may cause the open circuit condition), you can tack a good cap across the terminals of the suspect one (observing correct polarity). If that fixes the problem, then it needs to be replaced.As a newbie with electronics soldering, I bought a starter kit and a couple capacitors, then replaced C216 . I damaged the printed circuit when removing C217 so didn't replace this one
Same problem with Yamaha P95, (2012 production) no sound from speakers or headphones ( only led lights are on and operational ) after changing C216 cap P95 is working again the only problem I have now is when I press on- off on the keyboard it will cut the sound off from the speakers or headphones led power light is on no sounds at that point only power light is there (does not go off) when I unplug power supply and plug back on it works again sound is back keyboard is working to shut it off I need to shut it off from the keyboard or from the wall and than again plug it to the wall - keyboard on off is like not there will no do a thing .Could someone be helpful with that. Thank You very much.
But we hear that it cuts off the sound, and so the switch and it's wires must be OK. Does that same on/off switch turn it on when you want it to? Or do you have to unplug and then replug before it works?Hi JURECKI,
I have the same problem. Did you solve this? Or you change the AM or the DM board.
Thanks!
Juan
Tools used: phillips screwdriver, basic soldering iron with temperature control, solder (60/40), solder suction pen, multimeter, a 6-8" piece of thin (22/24 AWG) solid wire (e.g. from a spool of Cat5 cable), brain, patience, extra patience, swear jar.But we hear that it cuts off the sound, and so the switch and it's wires must be OK. Does that same on/off switch turn it on when you want it to? Or do you have to unplug and then replug before it works?
Here is a guess, which is that afterrelacing the failed capacitor, some connection is not in the right place. But having never seen the P95 I am not able to point at the exact cause.
Great to hear! I'm a bit hesitant and still haven't made the jump to try and replace my capacitors after the same has happened- did you remove C216 & C217 and then test them with a multimeter out of circuit? I'm just unsure as to how to test them before removing them. Very new to all of this / have minimal experience.My daughter's P95 stopped suddenly working. After a quick search I found this topic and I joined the AAC forum to download the service manuals (the schematic is only in the P85 one, so download them both). I started troubleshooting the issue in a "professional way" but then I accepted the initial suggestions to check C216 and C217 (where I found a different voltage) and indeed one of the two capacitors was shorted out. Luckily I already had similar parts in the box with "spare parts from previous projects" and in no time I replaced both of them (if one shorted-out it is logical to expect that the other will follow the same path).
It is also possible to verify the capacitors for short circuit using a multimeter with the continuity check function.
I have to say that the intelligent discussion in this forum saved me a lot of time.
Thanks to all the people that posted here. I added this report of mine to keep the topic active, because it seems that more and more people will encounter this problem sooner or later.
If the caps are shorted, you can test them in circuit. If they've opened, you won't be able to measure that, but you can put a known good capacitor in parallel with the one you have suspicions about. If doing that helps, then you know removing and replacing that cap will help.did you remove C216 & C217 and then test them with a multimeter out of circuit? I'm just unsure as to how to test them before removing them.
Yes I confirm the above. A short-circuit is a short-circuit so you can test them "in-circuit" (with power removed). Interesting enough, when power is applied, if you measure the voltage of each capacitor terminal with respect to ground, you will see different values. The circuit in that section is symmetrical (L and R channel) so the values should read the same: this was the first thing I did.If the caps are shorted, you can test them in circuit. If they've opened, you won't be able to measure that, but you can put a known good capacitor in parallel with the one you have suspicions about. If doing that helps, then you know removing and replacing that cap will help.
Blindly removing and replacing components is just guessing. When I was a technician, we called that technique "shotgunning".
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