MF#35 Synthesizer key fix repair on roland Juno
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- เผยแพร่เมื่อ 7 ก.พ. 2025
- Just a quick video to show how to repair non responsive synthesiser keys
I have to buy most items myself to make these video's so any help would be greatly appreciated "become a Patreon" / markusfuller
I inherited a juno 2 that has three keys all together not working, i was hoping it was a simple clean and here you are sir having a video and everything. Marvellous!
Thankyou for your tips, muchly appreciated. I expect a full clean will add another 30 years to this lady
How cool...I learned how the difference between the two contacts makes the velocity! Makes total sense now
omg. I've been waiting for years to get together the money to have the dead keys repaired on my Juno-D. I had no idea it might be this simple to fix! I will try this out over the weekend - thank you so much for this guide!
Thank you, Mr. Fuller, from your newest "fan" in Savannah, GA USA
Can't wait to fix my Juno!
Well done - cheers!
Note that when the carbon contact surfaces on these wear away, no amount of cleaning will help. Indeed, it will make the problem worse. However, you can buy this rubberized carbon compound for PRECISELY this purpose. A tiny dab applied to the strip contacts or toothpick traces on the board pads, then an overnight drying is usually more than enough to fix the problem. Less is more in these fixes as too much can lead to shorted contacts and "always on" keys. Also, if you don't want to open the board, sometimes some deoxit applied to the neck of the keys (a decent 3 or 4 sprays per bad key) and then drying for 2 to 3 days after playing the key 20-30 times will often clean any non-conductive material and treat the carbon surfaces to boot. Too much, though, and you can remove the carbon, so it's a tightrope repair, but both can work well!
Funnily enough, I've just bought an Alpha Juno 1 and this helped me in working on it!!!
Thank you for this tutorial. I have a Roland Juno D and several other keyboards, but because I usually control them through midi it wasn't for a long time that I discovered a few of the keys on the Juno D dont play a sound, even if you apply a bit of pressure to them. If you go up the scale you get gaps of course. I found this video and yes this video was very handy for me. I had an idea they would be rubber and carbon under there as I fixed a friends very old yamaha rhythm selection pad this way but never touched the keys side of things. I havent opened my Juno D yet but I think it will be molded keys in sections, I dont think it will have springs (hopefully). I love the keyboard as it has some fantastic orchestral sounds which have helped me countless times doing backing tracks for my late step dad when he was a singer for charity :) Thank you again. I have subscribed as I think your videos are worth keeping as reference and for interest in this field :)
Thank you very much! I just repaired one non functioning key on my Alpha Juno 1. Succesfully! :) Greeting Merijn (Holland/Amsterdam)
Thank you Markus, I tried it, and bad keys now works fine.
Awesome video, got to do this to my recently acquired W30 that decided to drop a note after I put it all back together having just replaced the backlight
The JD-800 has the same rubber plungers. Even cleaning didn't help, the contacts were so worn down that I could see the gray rubber where they should be black. However, Roland offers excellent service and sold me the rubber strips for just a few EUR. So I replaced them all.. should be good for another 20 years of heavy use ;)
Brilliant! I have this problem on this exact synth!
Jep! This is how you can *temporarily* repair those keys....They will again do their jobs for the next 2 to 10 years, but you have to do it again.....Even worse when you got to repair some "smoker units" i could tell you hours of stories about some dark brown sticky PCBs, KeyPads, rubber contacts and non working IC-sockets....
My "all-time-favorite" is the Matrix-6 keyboard. As it had already non-working keys as i got it. I cleaned it all up (just like you did in here) it worked for 2-3 jears and the promblems came back, went for another round but with the help of industrial carbon sticky paste to prevent further wear out.....but now i´m having the same old story....
The keyborad itself is simply is worned out (beond permanent repair), i may get rid of these lousy keys and convert it to an expander unit and (re)gain some space for another synth (WSA!) as well ;)
But this is a more complex project so i have to put this in some sort of a inline waiting...
Thanx Markus, for sharing!! GREAT Job!
Hoping that you´ll do a nice video on that "Spectrum Synthesizer" and showcase that unit to us:)
Any ideas of how to fix the after touch sensor. Its a well known problem on the Alpha Juno 2 that the aftertouch only works if you press the key very hard and put the coresponding parameter deaph way up. Anyone knows how to fix that or will I definately need a replacement of the after touch sensor? If so: where can I maybe get one? thanks
You should have mentioned that there are springs for black keys and ones for white keys on there. They don't have the same tension on them, so you have to put them on the right keys, otherwise your keyboard will have a strange feel on some keys if those springs were mixed-up. Also, isopropyl alcohol (rubbing alcohol) will do as good a job as the CD cleaning solution. But this is a temporary fix, as other keys will eventually also fail to make contact. Why not clean ALL the key contacts and not just the one that failed, since the instrument is opened and keyboard accessible ? And finally, sometimes even cleaning the rubber pads and PCB contacts will not restore a failing note. Then, applying a new coat of graphite to the rubber pad might be necessary, which is a bit more involved than simply cleaning, but not impossible to do for someone.
But I'm willing to bet $100 that the aftertouch wasn't working either on that keyboard, as the pressure resistive strip underneath the keys, from which you had to replug the strip on the left of the keys, will probably be oxidized over the years, requiring a very hard pressing down on the keys for it to work, if at all.
Hey There, is it possible to clean the pressure strip of the aftertouch??
Great video, i had some keys that didnt work at all and now they all do. But in randomly now some keys double trigger. Any tips for this ? i made the cleanence twice now.
I've been through a fair share of your repair videos and for a synth junkie such as myself, all I can say is I wish you lived nearby me in Canada! I have a Yamaha CS01 MKII that I'm stuck on implementing a Highly Liquid MIDI mod into it. You'd be just the guy to sort it no doubt! Haha. Regardless, you have a very useful stuff on your channel if you're into a bit of DIY repair and a bit of an electronics background.
Jay Kaufman Thanks Jay. I hope you get the CS01 Midified. I had one of those years ago ( grey ) It was a great little synth from what I remembered. Good Luck.
Thank you for this, Markus!
My mom taught me that same pattern for playing ascending notes. I never use it for playing, which I do poorly. But for testing the patch assigned to each key, it's quite handy :) I realized, after many years of owning synths and not using after touch much, after touch is probably mostly mono?
+Michael Bauers I wish I had some music lessons when i was younger. I still play chords from memory knowing the sound it makes but I could not tell you what chord it is called.
This was REALLY, REALLY helpful, especially to those of us who don't know one end of a multi-metre or soldering iron.
I do have a question - where can I get the springs for the keys for a JD800?
Hi Zoe. you may be able to get them from syntaur.com of there are sometimes people on ebay that break down old synthesizers and sell the spares there. I think there is a facebook group called synth spares and repairs or named similar to that I am not quite sure but always a possibility that you may find someone there. I always have problems getting parts. I hope you manage to find them.
Does this also happen with the Roland TR-505 drum pads when they stop working?
Hi Sir, I recently had to clean the contacts on my Roland Juno-D keys and I noticed inside on the right hand board where the effects pots are there is space for 6 switches and 3 leds on the board but nothing punched out or marked on the top metal cover piece. I wondered if you knew what they might be for as I havent seen a stock version of the synth with any extra functions. I am tempted to solder in the 6 diodes, 6 switches and 3 leds and drill holes for them on top to see what happens but I wouldnt want it to crash or knacker up the synth in any way. Thank you :)
Thats a really great video.
Is it likely to be something a bit like this causing a key to have no touch sensitivity - it is always full blast no matter how gently it is played? I have that problem on an old Roland D-50
HELLO MERCUS WHAT SPRAY YOU USED IN RUBBER CONTACT AND BOARD? PLZ. SEE THE PROPERLY YOUR SPRAY NAME AND BRAND.
I have a Juno 60 and a dx7iifd. if you ever find either keyboard to show up in your lab, I would love to see a teardown of either (or both!) :)
Hi Marc. If i get my hands on them I will certainly open them up :-)
Thanks!!! I was looking for something just like this.
I don't see how you remmoved the keys on this Alpha Juno 2. Mine has a clear protective strip on the backside running the length of the keyboard that prevents any key from moving backwards for removal.
yes you have to peel that off and reapply it with paper glue or twin sided tape. I may not have made that clear in this video. sorry about that.
hi excellent video. Is there a solution to a keyboard that has been aggressively cleaned. My Korg Poly 61 has been cleaned but I think the carbon has come off the rubber key contacts as hardly any of the keys work. Thanks
Hello You can buy the rubber strips that go along the board but they are quite expensive and theres many different shapes and sizes. I would contact Korg UK and ask to buy a new strip.
Hi. thanks markus that was very help full, I have yamaha clavinova clp 240 that have 3 sensores two for velocit, one for damper sensor when key plays with repetition, the problem is some keys randomly play at highest velocity even if you play them so softly ,
just like this video "Don't buy Yamaha Clavinova: Yamaha CLP user review"
i hope this method solve my problem, i wish some day you do this process on clavinova's
thanks again
Thank you so much. I will do exactly. Cheers!
Are the key switches designed as parallel circuits?
+alwerks1 Im not too sure now. it was a fix for a friend and I cannot remember now, too long ago. Sorry
Hello MarkusFuller,Please, I need your help. The following keys Ab4, E4, F5 and C5 are not working on my Juno 2, so I went ahead to strip off the keys apart and cleaned as you demonstrated on your video. Still the same problem persist. Pls, what do I do? What could be the problem? Thanks!
Hello Amos, sometimes the problem could be caused else where. maybe check all the ribbon cables are seated correctly from the keyboard to the main synth board. and then check all the diodes under the keys because if one has died (very unlikely) it may affect several keys as it works like a matrix ie if one row has lost connection then all the keys along that row will be disabled.
The famous 'Hoover' synth!
That does way more than that sound.
my juno g transposes by itself any pointers as to what i can do to solve this problem? thanx!
Hello . There seems to be quite a few people with this problem of the Juno-G transposing , there is a thread/conversation on the roland forums about this and nobody seem to know how to fix it. I don’t know how it is repaired but I have had your same question a few times from other roland juno-g owners and sadly do not have the answer. my apologies. heres one of the links to the roland website talking about the transpose problem. forums.rolandclan.com/viewtopic.php?f=12&t=17239
@@markusfuller yeah i read it, i want to say its the pitch bender that needs to b fixed, thats if people already tried fixing it through the software. I saw som brazilian guy open up the juno and do a "recalibration." Except idk portuguese. Ill try that, i hope i dont mess up the unit.
Is there an easy way to deal with crooked keys? I have a Moog Sub-37 with crooked keys and I'd love to straighten them out. :\
I could send it to Moog, but 1. That would mean being without my Sub-37 (separation anxiety lol), and 2. They seem to have had a bad track record on straightening keys so far, maybe they like them crooked!
Hope all is well :)
+Ronnie Perez I checked and couldn't find any listed.
thank you ;) best instructional video ever
Does Markus offer a repair service? Or does he only make You Tube videos now? Cheers.
monsterjazzlicks Hi , sorry I work full time and just don’t have time to take on repairs any more. I wish i had more than 7 days in a week then I could take on repairs.
Hi Markus, That's a shame as I would have used you for my Poly 61 Korg! Cheers, Paul Seaman
Hi, I have a problem with my Casio Celviano AP 38. I appreciate any kind of feedback.
Several keys (4 white keys in a row and 3 black keys in between) don't make any sound unless any four of them are pressed together.
There is one other black key at the other side of the keyboard, which plays well until one of the broken keys mentioned before is pressed. When pressed simultaneously, black key doesn't make any sound.
I wonder, if these symptoms could isolate the problem and show which element of the piano is broken. I tried to clean the keys and the electronic board under them, checked cables connections, but keys still don't work. Will replacement of the board under the keys help or this could be the problem of other elements? If yes, I will start looking for the new board in the internet.
Thank you!
+Valentine B Hello Valentine. It sounds to me like you may have a tiny crack in one of the tracks of the board that lays underneath the keys. this is rare but does happen occasionally. either that or a Diode within the matrix under the keys is dry jointed and only makes contact occasionally. Its just a theory but it seems possible as you have several keys in a row with the problem.
+markusfuller thanks a lot for your answer
my [value] and [page cursor] buttons on a juno d arent working..have to hit them several times to get an action, sometimes no action at all..how do I go about repairing that!
There may be a few buttons you will have to change. I changed a few in the video repairing the w7 , they are small clicky push buttons but very easy to find but you will need to solder them in.
thanks for that speedy reply..I'll follow your lead and get back to you if it resolves the issue..ta!
I've connected a midi usb keyboard to a Juno D because there are several
dead keys on the Juno. Everything works fine..plays performances, patches,
knobs affect the output sound...but when I select the [chord memory] or [arpeggio/phrase] button the sound is unaffected.
This was the main incentive for the setup as I really like playing around
with the [chord memory] or [arpeggio/phrase] buttons. However they still
work when I play the faulty Juno keyboard.
What settings do I need to make if any?
Thanks Dave
Hello David, I am sorry but I really cannot figure out what the problem is here. it is something I just do not know the answer to.I mainly only repair electronics and I am no expert when it comes down to midi communication protocols or the extra working parameters of some synthesizers. my apologies.
no problem.. I appreciate the quick reply.Im thinking its not going to be feasible, as the functions arent linked to a midi channel..but I'll wait and see anyway, and ask around! Thanks
How does one remove a key on the jx10? There's a clear plastic strip holding in the tabs on the backend of them.
Agreed. Nobody seems to mention this issue & I do not have the answer. Also I read that the black & white key springs are NOT the same, so be careful re-installing!
Excellent video Markus, really helpful as I got a second a hand Juno 2 few months ago with many keys not responding...
Moreover, the joystick came broken, too! :( do you know a place to find a new one, please? I tried many websites but no chance....Thank you very much in advance.
+Gully Foyle Hi Gully. I do not know where you can find a replacement joystick but I found someone making replacement buttons with a 3d printer for some synths so I guess there will come a time when someone will make one for you. at the moment Im looking around myself for these guys as I think it could be a good contact to have. If I find someone I will let you know.
Hi Markus, thank you very much for replying.
I've been thinking about the 3d option for some time now....I guess I will give it another try here where I live in Barcelona.
Many thanks again, really appreciate your feedback :)
You are welcome and Hello to Barcelona :-)
Thanks Markus!! Barcelona says you Hello, too. ;)
Thanks for your video. I have a Roland XP80, and many of the keys are stuck and won't press, because the epoxy glue that holds the semi weights under the keys, melted over the years, because I left my keyboard in my garage during the hot summer months and it was standing up on its edge. The epoxy has run down and into the key areas and many don't even push down because the glue has re hardened into them. I watched another video or two and someone else had the same problem. They used acetone as a solvent to break down the epoxy so as to clean it off of everything. So now my question to you is, will this work, and clean everything inside? Will I be able to get the inside parts cleaned along with the keys and get my keyboard playable again? I really like this keyboard and it was I, that neglected it for many years. I have been teaching myself the bass, so I backed off on my keyboard playing and now this has happened. I really wasn't thinking that something like this would happen. Is acetone the best chemical to cut that reddish epoxy down so I can clean everything? I haven't started any cleaning yet, but will be soon. Thanks for any help you can give.
Hello. wow that was an interesting question. to be honest I am not 100% sure acetone is the best way but only because I have not tried it myself. I guess it would work but I would only try it on one of the end keys first just to be sure it works. failing that I wonder if a hairdryer would warm up the epoxy enough to free the keys ? then you could maybe pick away the epoxy with a small screwdriver if you can get it soft enough. but I have never done this myself so I do not have the answer for you. Good luck and if you make it work please do let me know. Best wishes from Markus
Thanks anyway. If I can remember, I will let you know how it turns out when I get started and finished. Cheers.
markusfuller how does one begin a career in synth repair? is having a background in electronics necessary? can some take another person as an apprentice?
Hello, yes I believe Acetone will break down the glue but if it gets onto the contacts or the circuit boards im not sure what damage could result. I personally would try and remove as many parts as possible first then maybe use a hot air gun or hairdryer to soften the glue so i could pull the keys off one by one and acetone them away from the rest of the keyboard
Hello I worked many years in electronics and have keyboards and music was my hobby so I just melded the two together, If you know electronics you should be able to repair almost any synth with your knowledge of electronics. but if you have no knowledge of electronics then synth repair could be a bit difficult and it would be wise to learn some of the basics of electronics, once you get going everything you repair will teach you something new. Im learning all the time.
Where get the rubber contacts?, dust in keys and contacts is normal but rubber contacts broken is headache...
Wolfgang Rane Hi Wolfgang, I do not know where to buy the rubber contacts but Im sure if you got in touch with Roland they may be able to help. I have cleaned these up in the past but never had to replace them yet.
I have a Alesis Keyboard I wrote to them and in simple words.." Send your keyboard a technical service "..¬¬ .. to only replace a rubber !
+Wolfgang Rane google Syntaur. They have them in stock for JU2,6,60 and many other models. Most manufacturers as well.
+Wolfgang Rane Syntaur also carries Alesis contact pads as well.
Thank you!
I got a request... Can you play "Everybody in the place(fairground mix)" by "The Prodigy" on that keyboard please? thanks
Thank you so much!
I had a similar problem with a Korg Mono/Poly years ago (Great synth still).! I did exactly what you describe. It didn't help at all. Since then I heard many similar complaints about Korgs of the same vintage. Still wondering what the problem was though. The caps where not brittle. The graphite cores seemed solid enough. Maybe the carbon on these was also only a thin layer. Any idea?
By the way: Love your vids!
+Marc Brassé Hi Marc , sorry you did not get yours fixed. yes the carbon track is only screen printed onto the circuit board and sometimes its thinner on some than on others,
Typical, One would expect carbon not to be THAT expensive, although that would of course partly depend on the quality. The beginning of the "penny pinching aganst quality" movement? The woodwork of the Mono/Poly and Polysix where also very cheap. Almost Ikea quality. Still I loved that Mono/Poly. Conceptually it still is one of the most versatile analog synths ever and it sounded great.
The even older generations had real mechanical key contacts though. Under normal circumstances they last forever. But the bulk and price of such instruments where of course of an entirely different order. I just disassembled a mid 70ties Yamaha E70. It's remaining electronics and keyboard assemblies are still bigger than a complete portable organ of 10 years later.
Ah yes the Korg Mono/Poly, brilliant synth, I missed buying one of those a couple of years ago for a very good price. If I was 2 minutes earlier I could have purchased one for £20. still we cannot all be in the right place at the right time. :-(
That would have been an incredible steal indeed! I always say: Never fall in love before you've really got your paws on it!
I bought mine brand new short after its release. It's the only synth I really wish I hadn't sold but since I did it to finance buying my Yamaha CS80 my conscience is still reasonably intact.
Ah the CS80 . I would sell my mother for a CS80. oops I think she reads these messages.
how would you fix a non responsive after touch sensor?
very rare that these aftertouch strips fail. but i would check the connector where the strip joins into the connector, maybe use a multimeter on the 2 or 3 connectors and press down on the keys to see if the resistance changes. they are all very similar in design and you could probably get one out of an old synth even different manufacturer and swop them over.
+markusfuller awesome! thanks, I'll try that :)
great video. Thanks
Thank you mate! :D
And Bob’s your Uncle !
what a beautifull scratch sound when cleaning the board... :+D ;)
Thank you!