SUCCESS STORIES: Yamaha Keyboard P-95 sound problem (speakers & headphones)

It may take me a few days to get back to it, but I will definitely post some photos. I didn't consider point to point connection, thanks. Back soon...Tony
 
Dennis,
A near genius, you are. According to your suggestions, I cleaned up the mess I made of the circuit and soldered jumper wires to a connecting node. All is great on the keyboard. Thanks 10E6!...Tony
 

dl324

Joined Mar 30, 2015
14,317
A near genius, you are. According to your suggestions, I cleaned up the mess I made of the circuit and soldered jumper wires to a connecting node. All is great on the keyboard.
Glad you were able to repair the damage, but you give me too much credit.

The technique of connecting open traces with wires has been around for decades. I learned the technique when I was a technician at HP in the late 70's. Board defects on multilayer boards were common back then. They even gave us training on the proper direction to wind the wire around the leads.
 

serifpersia

Joined May 19, 2020
13
Hello GermanCoca,

Thank you SOOOOOOOOOOOO much. I had the same problem and solved it with a single shot, thanks to your experience.

I would like to add a small contribution. To test whether the problem is on the headphone path, it is easier just to disconnect the HP board completely and connect HPSW node to GND on AM board, instead of desoldering C217 and C216. If the problem is the same, the speakers should start working.

I am curious if this is just a coincidence that among all other capacitors, the same were problematic in both cases. Here is the only misuse I can think of: I recently bought a sennheiser hd558 headphone whose cable can be detached from its speaker. When I was using my piano I used 3m cable and when listening to music, I switched to 1.2 m cable while leaving the 3m cable on piano, with its other end open. I touched that open end many times when I switched from playing on the piano and listening to the music. Do you guys have any idea if this could cause the harm mentioned above?

Thanks again GermanCoca!
Hi there I'm planning on buying a p95 and it has the same problem with speakers/headpones. What do you mean by connecting HPSW node to Ground on AM board?
 

serifpersia

Joined May 19, 2020
13
The thing is I never got to do a proper solder job so replacing caps is a no no but the saw others suggesting the node to ground thingy, So all I have to do is disconnect the headphone board and amplifier board from the headphone side and then connect pin 4 and 5 on the amplfier side of the connector with a wire? Is this correct. This will get me the speaker sound but the headphone port will not work right?
 

serifpersia

Joined May 19, 2020
13
Oh I forgot thanks for the welcome. Today I found this p 95 for $131 (120EUR). I use a crappy 61 key midi keyboard and I want to play piano like action. Thanks again!
 

serifpersia

Joined May 19, 2020
13
Another user posted pdf that had pcb schematic for p85 which has the same electronics as the p95. So the pin no 6 is on the far left and pin no 5 is next to it. A small wire will be connecting those pins and it should resolve the audio if not I will just use it as a midi controller.
 

Attachments

Hey, I really appreciate every contribution to this thread.

I recently picked up a P-95 on OfferUp, great deal too but the caveat was that it had a no sound issue like everyone else here. Today I bought a new EC for the AM board, but holy smokes did I bork it with my basic home solder kit. I wish I could just buy a replacement AM board and be done with it but now i'm tempted to have a local electronics shop try to undo the trace foil damage I did removing C217.

Just curious, could I have one of those online PCB build websites replicate the WK351200 or am I totally forked?
 
First, thanks for the huge amount of info from this thread. I have a P95 with the exact symptoms, no voice. Long story short, I identified the bad capacitors and purchased replacements. When I was replacing them, I either overheated the circuit board or my trusty soldering iron is overheating. Either way, the capacitor will not solder in place because of the foil trace damage. I tried a carbon pen but was unsuccessful. Most depressing since I thought I was pretty competent with a soldering iron. Anyway, I am now on the hunt for a replacement AM board (Yamaha part # WK351200). Anybody got a spare or a source? Thanks...Tony
You let me know if you find one. Someone on this thread was quoted 250 GBP for a replacement from a repair shop I think, but it begs to ask how the shop could source one and we're scraping the internet for one... =[
 

serifpersia

Joined May 19, 2020
13
Update: The Yamaha P95 arrived yesterday and It works just fine as a midi controller. Today I tried to fix the no sound issue by disconnecting the cable that connects the am board and the hp board from hp side and I placed a wire in between pin 6 and 5 on the connector on the am side. Sadly I still hear the relay after 2-3 seconds of turning on the piano. So does this mean that those two caps aren't the problem? I will get a multimeter and If I find shorted caps I will inform you. Luckily I have a neighbor who can solder stuff and I hope we can fix this issue.
 
Welcome to AAC!

Read post #60.
Oh yeah, in fact it was your advice that inspired me to rescue it with my amateur soldering. Except I only butchered it worse, and probably because I didn’t use flux (—does a rosin core solder help?) during the melting phase. I then tried to loop the length of the new EC around and back down to the board across the damage. Atrocious. I’ll post pics later if anyone needs a good laugh.
 
Do they even make solder that doesn't have a flux core? I rarely use additional flux.

What is the wattage of your iron and its tip size?
Oh man, prepare to witness total chaos. I used a little 30W Radio Shack Kit iron. I’m thinking if I can heat the solder between these two points (—you’ll see what I mean when the photo loads) it’ll form a literal bridge and maybe bring continuity from the EC217 to Pin 4. Please advise if I should scrap it and just clean it up and start from scratch with this thing. I won’t give up on my first piano, and I love tinkering with electronics so I’m determined to see this through. Look at how tall my new sits compared to its OEM sibling.
 

dl324

Joined Mar 30, 2015
14,317
Sheesh that trace foil damage would make my old instructors from BMT cringe
If the points circled in red are connected, you should be good to go.
clipimage.jpg

For good solder joints, less is better in this case. What diameter solder wire and iron wattage are you using?

Looks like you're touching the solder to the iron and not the lead and pad where you want the solder to adhere; so you get blobs of solder instead of a metallic bond.
 
Last edited:

MrChips

Joined Oct 2, 2009
25,928
You are using too much solder.
The biggest mistake noobies make is melting the solder on the tip of the iron. As dl324 says, you heat the joint first and then apply solder to the heated joint. It helps to get the solder flowing by touching the solder between the tip and the joint (while the tip is still touching the joint, i.e. the soldering tip never leaves contact with the joint while the solder flows). Total time is 2-3 seconds.
 
Top