YAMAHA Keyboard disassembly PSR-EW300 key & felt repair

[@rorypenstock1763]

At 5:36, I initially wondered how the keyboard can detect a continuum of hard and soft key strikes with only two sensors. You kind of glossed over this in the video, but I imagine this is how it works: The reason for having one high and one low sensor is not so that you can press a key halfway down and get a different response, but so the keyboard can detect the velocity of a key press. When playing a keyboard, you always press each key all the way down,* no matter how soft the note. By measuring the time between the first contact and the second contact, the keyboard can determine how fast the key was moving and adjust the volume of the note. I didn't know this was how velocity detection worked, but it's pretty clever. I say "volume," but actually, the MIDI interface has a property called "velocity" for each note, which is exactly this measurement. Most MIDI synthesizers use the velocity information to vary not only the volume, but also the timbre/waveform of each note you play, as, for most instruments, the difference in sound quality between a loud and a soft note is more than just amplitude. *Keyboard instruments require more force to depress a key than to hold it down. On real pianos, this additional initial force is due to the inertia of the hammer. On traditional tracker-action pipe organs, the key is mechanically linked to a valve that has to be opened against air pressure, but which, once opened, offers no more resistance. Electronic keyboards are designed to mimic this behavior that players have come to expect. I was going to write about all the different ways you could do that, but I've gone on long enough. Anyway, this would make it hard to press a key only partway down. Great video as always! As you can see, it gave me a lot to think about.

[@pocket83squared]

Without knowing for sure, I'd have to say that you're on the right track. Even if this particular keyboard isn't using 'velocity detection' to modulate its sounds, it sure _could_ be. It's just software. Those two pneumatic hoses lying on the road do the same thing. After a tire runs over the first hose, it's simply a matter of measuring time until the second air hose is struck. Thus we have directional speed: a car's velocity.

[@SianaGearz]

You are 100% exactly correct. To employ a high scanning rate and provide sufficient timing resolution between the two presses, i have seen some MIDI instruments from mid 2000s use an FPGA. On a Yamaha i think you often see an ASIC (special purpose IC) which does the scanning. I wouldn't be surprised if it turns out they spun the scan ICs once in the 80s and just kept reusing it for a very long time, with refreshes only for cost as needed. Nowadays you often see an STM32 doing the scanning and i think they use an internal configurable DMAC peripheral to make it really fast, i suspect. I have been puzzling about how AKAI pads work. There are no two separate areas that are pressed at different time in pad travel, it's all one surface. They sense resistance, there is a special black material between the silicone pad and the PCB screen printed onto a PET sheet, and it continuously changes resistance depending on pressure, but it occurs to me from the play feel that they do actual velocity estimation as well, just from regular analogue readings. There are exactly as many pads + potentiometers on an LPD8 as the number of analogue inputs that the STM32 they use has, 16 total. All analogue inputs are connected via an internal multiplexer to a single ADC, so the readings cannot be taken continuously or at the same time, every time you switch the multiplexer you need to let the ADC settle into a new reading, which takes a while, i forget how long. At least on STM32 you fortunately don't need to stop the processor to take a good reading and avoid interference, you just need voltage and ground treatment external to the ADC section of the chip.

[@BlackPixxelDE]

This is very insightful, it was the reason why I watched the video. I expected each key do have a potentiometer or something to measure the velocity and angle, but this is such a nice and simple solution.

[@davidtrost4117]

One of the best instructional videos I've ever seen on KZbin.

[@pocket83squared]

Nice of you. Thanks. Hope it helped.

[@homunkoloss6782]

i felt very comfortable watching this video :) made me want to come back to some of your older videos again

[@qwadratix]

Thank you for this video. One or two of my keys have stopped giving me a predictable velocity response. I was wondering if I should investigate the innards or save the time and trouble. Clearly, it's a piece of cake to open and fix. Props too to the manufacturer for not trying to make it impossible.

[@DrewLukac]

Aside from always looking forward a Pocket video, I really enjoy seeing your shop dog just sitting there almost listening to you.

[@pocket83squared]

She's anything _but_ a shop dog! She hates it in there. It's pure boredom. A working dog like that will need a solid three runs a day in order to keep that patience in place. After a few hours, she'll whimper, I'll cave, and we go for a quad ride & play some dog-disk.

[@Subaru_Natsukii]

i know this video is a year old now but it really helped me, i bought an EW310 used and want to take the keys out to clean off marker from the last user and make sure the inside is clean and dust free. thanks for the detailed disassembly video

[@lukearts2954]

I've never opened up a keyboard. I was a bit surprised at how they used the plastic's elasticity as key spring (together with the springiness of the silicone button)... Awesome tip about the oil in plastic. I'm sure it will also avoid the screw catching before it has reached the original cut in the plastic side... I've had that happen to me so many times, ruining the whole thread after a few times opening and closing, but no more! All thanks to you :) Also nice work on the felt. I'm not sure if I would have tried to clean it... I'd probably have done a half job and just cut out the bad part (and cause those keys to feel different ever so slightly). You just showed that doing a decent job does not need to be more effort than a half job...

[@Vote4Drizzt]

I watched a video I have no use for, in a feed filled with channels trying to get me to click( even channels with integrity seem to make peace with the algorithm) just because I want to hear what you say while you do it. I hope that description explains the way in which I value what youve chosen to share, even when I disagree

[@RidwanTanvir]

DIY fixing videos should be like this.

[@pocket83squared]

Some of them are! They're just buried under a mountain of ad/sponsor-saturated high-engagement garbage. Some of my best content is way too boring to get clicks.

[@3006spikespiegel]

OH OK so we are doing this now.... Pocket is good at wood working... good at creating puzzles... does maths and philosophy... and NOW he plays the piano...How am I supposed to match all these skills But great to see your videos AS USUAL

[@npcsina]

Straightforward and informative, thanks.

[@TheRadYears]

The first two minutes of this video is like a Count von Count segment - My kids love it

[@pocket83squared]

Whenever you're taking something new apart, childish clarity is probably what you're after. _Eight. There are eight in an octave. Ah, ah, ah._

[@godfreydesilva5222]

Excellent demonstration. Thank you very much.

[@jamesgilbert6363]

Very good video. I have three broken keys to check out and order parts.

[@MrBecker666]

👍I just got a psr-300 for $5 with 2 broken keys so I’ll fix it looks similar screws

[@justinavery4047]

Thanks for this video I just got a 20 year old PSR-290 and was wondering how the touch response worked.. It uses the timing of the two contacts on the buttons.

[@ehsanarefi250]

Nice one. My problem is the power button which doesn't work and needs cleaning. I guess need some more screws to access this one.

[@SteveHameister]

Thanks for helping me fix up (decatpissafy) a second hand synth. Wasn't sure what to do about that felt.

[@pocket83squared]

In that case, vinegar is almost certainly the trick. Happy for you if it works. Thanks.

[@Wordsnwood]

You forgot the retro-bright... oh wait, this ISN'T the "8-bit keys" channel! 😉 Seriously, that tip about putting a touch of oil on the screws is something I've never heard of before. Good one.

[@pocket83squared]

There was this one video of mine a few years back that was probably half an hour long. Presumably you watched it, because you dropped a comment relating to how it's a shame that something in it worth hearing will probably get lost. That was a super compliment, by the way. We get only a pair or so of genuine compliments like that out of perhaps a million views. If memory serves, it was about my old boss yelling at us to remember that _how much_ money we made was irrelevant in comparison to _how we use_ that money. Turns out he was right. Using a drop of oil on a metal screw that's going into plastic? That's also one of those game-altering tips that most of us are just too impatient to accept, at first, until we've become fully ripened by adulthood. The alternative, as I once heard @AvE mention, is to tighten it until it cracks, and then back it off a ¼ turn.

[@dwightl5863]

I would also add to screw into the same threads the screws were in originally. Makes for much easier assembly not "cutting" new threads. Also works well for wood screws i.e. taking down and reassembly of furniture.

[@pocket83squared]

@@dwightl5863 Agreed. If you use oil, it's pretty much certain that you won't re-thread plastic holes. Bar soap works for old wood things. I tried to imply this in the video, but I can't go down every path, for the sake of brevity.

[@SuperScottCrawford]

6:50 The magic juice! I use 91% alcohol to remove gummie adhesive residue from ALL surfaces with no damage.

[@bstein9500]

Excellent video. Thanks.

[@magdalenaodnaglosnienia]

According to the oil in the screws, does not the oil damage the plastic?

[@pocket83squared]

Mineral oil comes in a plastic bottle.

[@FTen2K5]

Have the PSR-500 keys have a slightly different setup. Can’t figure out how to remove them yet

[@WilliamAshleyOnline]

Other PSR keyboards are very similar in design especialyl for the keys

[@kuuhaku2543]

How do I put the rubber membrane back help

[@gideonmtonga4260]

Hi, I really enjoyed your presentation. I have had s imilar problem on the same keyboard. I have cleaned it twice and the keys will stop working again after a few days. What could be the cause?

[@pocket83squared]

Do the keys cut out altogether, or do they just seem to get less responsive? Is it only one key affected, or is it a group of keys, or the entire keyboard?

[@sireavant]

@@pocket83squared in my own case, it’s just one key that keep on stop working after few days

[@thomashverring9484]

This is an absolutely excellent video! Thank you :^)

[@pocket83squared]

My pleasure. Thanks.

[@MusicEnthusiast]

What's the price of keys set...

[@robertmccluskey3294]

What about psr 85 someone gave me a used one it doesn't turn on the guy said it does and three keys are broken can they be fixed

[@nunll4034]

Hi,What kind of double-sided tape should I choose for fixing felt strips? Ordinary double-sided tape has poor adhesive properties and is very greasy.

[@pocket83squared]

I used spray adhesive and masking tape. You're asking me to recommend something that I didn't really recommend. If you must use DST, then look for the heavy-duty stuff, and not the stuff that comes in a plastic dispenser. Note that it will add thickness.

[@nunll4034]

​@@pocket83squared What size of top felt strips did you use? I customized a 6*6mm felt strip because the height is too high. After tightening the PCB screws, most of the buttons will become unresponsive.

[@mikeburton1703]

i have a 310 similar to the 300......several of my black keys come across very loudly.....is there a way of toning those couple keys down....i would love for someone to tell me a fix.... it not fun to play when a loud black key is too loud thanks

[@JohnBender1313]

I know you do your thing and that's cool. But as a long time watcher I'd love to see you make a puzzle or something like that again.

[@pocket83squared]

Understood. Thanks.

[@JohnBender1313]

@@pocket83squared thanks pocket

[@cymaticCS]

I saw those hollow keys and I thought they could feel or work better if you filled them with something not too heavy, so that they don't bend down by them selves.

[@KyleWhitlock-Music]

Hey I wonder if the felt replacement on my MOXF8 keyboard is the same basic procedure as this keyboard? Anyone know out there? There are no Yamaha repair technicians in the area that I live in.

[@writofmandamus]

I have this keyboard and What I find strange is only the E's and Bb's that are on the top half of the keyboard don't work (total of 7 keys)!

[@writofmandamus]

Figured it out, just had to factory reset!

[@kwandonald]

would commercial contact cleaners be better than 90% Alchohol. Also what kind of cloth did you use to wipe?

[@pocket83squared]

Yes. Cotton.

[@ezeoandreicadungog2312]

Hey, does this work with any keyboard? More specifically the Yamaha Np-32?

[@melvinmejia8290]

thank you, kind sir!

[@VagabondTE]

Pocket showing us the key to piano repair

[@pocket83squared]

That's right, take _note!_

[@VagabondTE]

@@pocket83squared Oh, how do you do italics on KZbin comments? I know bold is with two asterisks.

[@pocket83squared]

@@VagabondTE Two underscores.

[@VagabondTE]

@@pocket83squared Ah _thank you_

[@edide1627]

This video made me sad. I had one almost identical and my brother asked to borrow it one time (he with his "band" were using our garage to practice for a gig), one of his friends our neighbour took it home to practice with it for a couple of days, my brother then moved out for work (living quite far away/ different country long time now). The worst thing is I sometimes hear my neighbour play it and I can't ask him for it back cos it wasn't me who loaned it to him, and he probably thinks that it was my brothers and that my brother doesn't even care about it, my brother is a guitar guy anyway.

[@pocket83squared]

Strange situation. Sometimes honesty has dark areas for the sake of decency. Now you've become trapped in a sort of drop-the-subject relationship, effectively making the neighbor impossible to befriend. With this in mind, since he's already _not_ your friend, you have nothing to lose by explaining the situation to him, and straight-up asking for it back. This, assuming your brother can't/won't do it for you, since he probably still should. If you're a prick, which doesn't seem at all likely, you could even demand it back, since legally it still _is_ yours if you have some record of the purchase. Here's what I'd do; you might try enticing the neighbor to return it with an honest (lesser) trade. You know, offer a gesture of goodwill, like this: _tell you what, if you give me back my keyboard, I'd be happy to give you this old bike as a thanks._ Whatever the solution is, it'll involve restoring honest communication. Unless you decide to steal your own keyboard back, which of course is ethically questionable. Um, well, depending on the neighbor.

[@edide1627]

​@@pocket83squared I'm from Kosovo-Balkans, and since last night Serbia's (our eternal enemy) special military forces are right on our border threatening to come inside (basically starting a new war again), so perspective I guess... I remember as a teen stress-playing that keyboard during the last war while watching news of massacres and all kinds of atrocities this same military did during the last war 2 decades ago. Life finds the strangest of positions to f... us over sometimes.

[@pocket83squared]

​@@edide1627 It fascinates me that you live in such an old part of the Western world. In comparison, where I live is quite young. Consider that the original old-growth forests of my area have just now been cut for the first time. There are no ruins from ancient structures here; in fact, in the deep woods, the only anthropological sign one is likely to see is the occasional stone foundation. One is even less likely to find an old well. Rarest find of all is a flint 'Indian' arrowhead, from the first human occupants of these woods. You and I live in different worlds. As far as I understood, the Kosovo war had ended over a generation ago. Please excuse the limitations of mass media; it tends to distract us with emotional silliness, so threats of hostility & their stresses often go unreported here. After looking over the Wikipedia page, I now understand that the rift between the two groups hasn't even begun to heal. Hopefully the tension on the border will ease. Unfortunately, what frequently accompanies an old culture is an old conflict. Here, at least our petty, partisan bickering remains mild at this point, though it does seem sometimes as though an old Civil war hostility is bubbling up again. I can't imagine it becoming like what you have already witnessed. You have my respect and sympathy. My question to you would be about what you think is perpetuating this war. The demographics suggest that there's a sharp religious divide between the two sides; is this the source of the conflict? In my country, religion is important to most people. The U.S. is a heavily Christian nation. So much so, in fact, that we're often biased to forgive acts of hostility by (other) Christian nations. As a secular person who has received formal education in science, I find such arguments difficult to tolerate. Aggression is something that simply needs to be stamped out, no matter the instigator.

[@edide1627]

@@pocket83squared I'll write to you later some day. Spilled a cup of hot coffee on the keyboard 1 month ago some keys stopped working the last couple of days now, having to use the "On-Screen Keyboard" to type using the mouse for some keys that stopped working. Actually, I wrote you a very very very long reply (probably been typing for an hour now) and somehow accidentally deleted it and right now I'm as pissed as I can be. My hands and fingers are hurting, was so close to smashing and throwing the laptop in my yard from the window and I will as soon as I get some data out of it (thanks to those this piece of shit of a laptop is still alive lol). Can't be repaired, can't even open it and I worked in IT for 5 years (never seen something like this) long story... You know how it is when you're almost finishing a project and then somehow you lose/destroy/break it (because something out of your control happens) or you get an idea for something (whatever) and you forget it before writing it somewhere, you feel like it would've been the best thing ever the best idea ever, the best comment reply ever lol... (even though in reality it probably was... sort of average) Have a nice day, here now is 4:20 AM

[@VagabondTE]

My biggest problem with electronic repair is doing everything or closing it back up within one day. Every time I leave something open to come back to everything goes the heck.

[@pocket83squared]

Been there. At least an open keyboard makes a great parts tray. A few _other_ open electronics projects could fit nicely inside it ;)

[@Stinkman]

I guess it's a music day for the both of us. I just had to repair my strap button on my guitar because the screws were stripped. Thanks for the upload, my dude. I know it's off topic, but are you aware of the mobile ports of the GTA trilogy being called 'the definitive edition?' Do you have any thoughts about that shituation?

[@pocket83squared]

Yes, one could say that I do. [scoffs] The only thing that a new release of the GTA trilogy will _define_ is just how blithely accepting the new game consumer is. They've removed tons of the original music: that alone should be a deal-breaker. "Improved"? "Enhanced"! You must be joking. The original works-warts and all-are what established Rockstar as a powerhouse of masterful gaming in the first place. Alterations, however mild, disguise context, and thus should be considered taboo to any purist gamer. The revisionist history we already suffer in (other) mass media is bad enough. Keep the f--- out of my games! So far, Rockstar has been _the_ purveyor of first-class satire in the gaming world. Maybe the re-selling of an "updated" yet still inferior version of their best product is one of those thumb-your-nose jokes; if so, I can dig it. But it's not so subtle. Thus, any kid out there who's willing to buy such garbage must be just as thick of a trope as any of the NPCs of _BULLY._ Wonder if the _Fudge Packing corp._ (and that Facebook-ish logo) will survive the enhancements. Or should we only be looking at our old jokes through our newest lenses? Now that I'm thinking about it, those working girls shouldn't get so mistreated, either. How many patches before they're no longer your original pants?

[@freetolook3727]

I just cracked open my computer keyboard to clean out years of breakfast behind the keys. 😂

[@pocket83squared]

Yummy. Makes one think twice about licking those cheeto fingers, eh?

[@cristibaluta]

i can't believe what primitive technology is yamaha using. I had this type of rubber buttons on my remote control when i was a kid, and it was always broken because the conductive material was shaving off. I watched this video because i didn't understood why they make the pianos bulky, and still don't get why

[@pocket83squared]

There's nothing "primitive" about it. In terms of simplicity, affordability, and dependability, this thing is downright well-designed. Conductive material separation could be from either liquid damage or a low-quality board; it would have little to do with the silicone buttons. Note that the Nintendo Entertainment System was released in the mid-80's, and there are still many, many controllers out there, in use. Its buttons use a similar design. Had they used some sort of touch-sensing buttons instead, every NES would be landfill by now. And same goes for most TV remotes.

[@Socmytoes]

😢😮😮

[@stepheendaniel3927]

Your 👌

[@user_i9]

1st hi 👋

[@pocket83squared]

2nd hey 😊

[@freetolook3727]

What did you win? Hi.

[@aileenduncan1317]

Great video, although the urine comment was freaky and completely unnecessary.

[@pocket83squared]

There's a good chance the substance came from a cat, in which case it's useful to remember that vinegar will break down the solute. I try to make my videos a golden shower of useful information, and I didn't mean to piss you off. Thanks for the helpful comment, squirt!

[@JThriftybee]

:)