Roland JV-90 Expandable Synthesizer


I picked-up an JV-90 last week for little money. It’s a bit dirty and a handfull of keys don’t work. I wanted a 76 keys synth again so I’m going to fix this one up ๐Ÿ™‚

Technical specifications:

  • Polyphony – 28 voices (expandable to 56)
  • Oscillators – Digital Acoustic simulation via 4MB (expandable to 14MB) of ROM
  • Arpeg/Seq – None
  • Filter – Digital filters
  • Effects – 2 effects units with chorus, reverb and delay
  • Memory – 256 Patches (can expand to about 600); 64 Performances
  • Keyboard – 76 non-weighted keys (responds to velocity and aftertouch)
  • Control – MIDI (8- to 16-parts)
  • Date Produced – 1993

At home I’ve tested the synth before I took it apart. Indeed a few keys didn’t work but what concerned me was that when I played a patch it sounded like a sustainpedal was attached and someone was pressing down on it. Even when you switched patches you would still hearย the previous patch.. After a factory reset of the synth this problem seems to have disappeared. Hope it stays that way ๐Ÿ™‚

I’ve put the synth in testmode and discovered that about 20 buttons don’t work very well. I’ll be replacing a lot of tact switches on this one. The aftertouch actually works but you have to put quite some pressure on the keys. I’m going to find a solution for this to. It usually involves soldering a resistor on a circuitboard somewhere.

Taking it apart:

20150829_134125 (Medium)ย 20150829_100436 (Medium)


First cleaned the keys. The JV-90 doesn’t have a semi-weighted keybed like the JV-80 and JV-1000. This is a shame because semi-weighted keys play better (my opinion). On the other hand; it saves me hours of waiting for this freakin’ red glue to dissolve in caustic soda ๐Ÿ˜‰

Dirty keys soaking in the kitchensink:

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While letting them soak for a while I cleaned the metal frame of the keybed which was pretty disgusting:

20150829_134129 (Medium) 20150829_134125 (Medium)

Placing the contacts and contactboards underneath the metal frame is brilliant. This prevents a lot of dust and dirt from reaching the contacts. The rubber contacts and circuitboard where pretty clean on this JV-90. It’s just the metal frame that is dirty. Check these pictures of my D-5 and JD-800 projects below to see what the contactboards look like after a while (decades) when placed on top of the metal frame..

SAMSUNGย 20150621_154458 (Medium)

It also makes servicing the instrument easier as well. You don’t have to remove the keybed from the synth (not a very easy job with a JV-80 / JV-90) and you don’t even have to remove the keys if you just want to clean or replace a contactstrip. Just removing the bottom plate of the synth gives you instant access to these parts.

I removed the contactboards and cleaned the rubber contactstrips and the boards:

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And reassembling again:

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I’m pretty sure all the keys will work again now. Only about 5 were not working before but I won’t know until I reinstall the keybed in the synth. Before I do that I have to remove all the circuitboards to replace these tact switches..

tact switch

Will update soon!

Update september 2 2015:

The JV-90 has +- 64 buttons and about 20 of them don’t work (very well). I have 30 replacement tact switches in stock. Hmm.. replace half and risk having to take it apart in the foreseeable future to replace more? No. I’ve decided to replace them all. The shop I usually order these tact switches from charges 0,15 euros a piece. Not very expensive but I’ve decided to order 200 from Ebay at 0,0325 euros each. It’ll probably take a week or two before they arrive though..

In the meantime I’m looking for a Roland JV-1000 synthesizer. They look very cool and I’ve always wanted one. There’s a project one I’m going to try and buy from someone. Hope that works out ๐Ÿ™‚

Update september 15 2015:

The new tact switches haven’t arrived yet but since I had 30 I figured I just start with the job anyway.

Taking the JV-90 apart:

20150909_194239 (Medium)ย 20150909_194859 (Medium)

20150909_195657 (Medium) 20150909_195653 (Medium)

As you can see in the pictures I’ve removed the switchboards and they are dirty ๐Ÿ™‚

I desoldered all the tact switches and cleaned the PCB’s. You can see that there is a lot of dried up residue on the boards. Probably something like WD-40.

20150909_201308 (Medium) 20150909_205953 (Medium)

After cleaning and replacing some switches:

20150909_202205 (Medium) 20150909_203754 (Medium)

I cleaned this with alcohol and the boards look nice and clean again. I replaced all the switches on one board. Have to wait for more switches to arrive to finish this job.

Some more pictures of the dirty insides of the synth:

20150909_195832 (Medium) 20150909_195644 (Medium)

Update december 3rd 2015:

I’ve replaced all the tact switches and they all work fine again. I’ve put the synth back together and tested the keys. Some still didn’t work. Took it apart and cleaned the contacts underneath those keys again (several times) and now they all work.

Still 2 problems:

The volume slider works very badly. The synth only outputs sound on the right channel at 99% of the travel of the slider. There is only one tiny spot where I have stereo sound. I have desoldered the slider and taken it apart, cleaned it but it was clear the the slider was worn out in the inside. Cleaned it anyway and put it back together. Soldered it back into the synth and now it works even worse :’) I’ve contacted Roland to order a new one but they cannot supply them anymore.. I’ve ordered these before a year ago so that’s a bummer.

The other issue: the sustain problem. Sometimes when you switch it on it sounds like there is a sustainpedal attached and you’re pressing down on it. Very weird. If I press the panic button combo it goes away (and stays away) but it can come back the next time you switch it on.. not really a disaster but it makes me wonder what to do with this synth. Part it out or sell it as ‘functional with minor issues’ ๐Ÿ™‚


Yesterday new parts arrived from

Finally I have the new volume potentiometer. I soldered it in place and put the whole thing back together.

The volume control works fine again now! ๐Ÿ™‚

Still two minor problems: one key isn’t always velocity sensitive and when you power it up it still has the sustain problem.

I’m going to see if painting the contactsย for the one key that doesn’t work well with conductive silver paintย will fix it. I’ve read that people use this stuff for this application and that it works fine.. I have this paint so I thought I’ll give it a try.

20151225_110553 (Medium)

The sustain thing is really weird though.. it’s not really a problem but it isn’t supposedย to do this ๐Ÿ™‚ all the notes you play will continue to sound untill it runs out of polyphony. Pressing the panic buttons solves the problem immediatly. It stays away to for the rest of the session..

Update january 16th 2016:

I ended up painting 3 or 4 contacts with the silver paint for everything to work fine again. Still everytime I powered it up it had this weird sustain problem. Until I connected a sustain pedal to the HOLD port on the back at some point. That seems to have fixed it ๐Ÿ˜€ probably dust or dirt in that port.. works fine now.


10 thoughts on “Roland JV-90 Expandable Synthesizer

  1. Hoi Jorick, leuke site. Ik ben ook zelf met de restoratie van een jv90 bezig en het is heel fijn om te zien dat je de moeite hebt genomen om het process vast te leggen en online te delen. Ik heb al ervaring met mijn xp-60 en die tact switches en ik heb ze via farnell besteld a 10eurcent/st. Kort geleden een jv90 gekocht en jahoor die had ook meer dan de helft van de tact switches stuk. Uiteindelijk de 64 moeten vervangen maar nu nog de aftertouch die heel erg ongevoelig is, dus binnenkort zal ik een update posten over hoe en welke aanpassingen nodig zijn om hem te fiksen (ben zelf electronics hardware ontwerper). Heb je toevallig ook het probleem van de ongevoelige aftertouch in die jv90 van jou? Gr.


  2. Hoi Hugo, ik heb inmiddels alle tact switches vervangen van de JV-90. Alleen de volume slider geeft problemen. Ik heb hem open gemaakt en hij is echt totaal versleten. Ik heb geprobeerd via Roland een nieuwe te bestellen maar ze zijn niet meer leverbaar.. Ff kijken wat ik daarmee ga doen. Aftertouch heb ik nog niet getest maar die doet het ongetwijfeld slecht ๐Ÿ™‚ Ik ga dat binnenkort bij m’n JD-800 proberen te fixen met een weerstandje en een potmetertje om de gevoeligheid af te regelen. Zijn die Farnell tact switches ALPS? Die ik gekocht had bij zijn volgens mij ook gewoon goedkope Chinese. Je kan ze herkennen aan het harde klik geluid dat ze maken. Veel harder dan bij de standaard switches. Ze doen het overigens prima..


  3. Hoi Jorick, verder in het Engels voor de bredere audience ๐Ÿ™‚ Alps seems not to produce the tactile switches anymore but other respectable brands do. Tyco (TE) for instance is a reliable high quality one. You just have to look for the “pressure/force” spec. The Alps/panasonic switches Roland used (13169752/EVQ 213 05R) had an actuator pressure of 1.3N, so choosing a switch around that pressure 1.2N-1.5N should be fine. I ordered the original ones here (in amsterdam) but they are available at Mouser too The volume slider is indeed a challenge, but if you look at the schematics, the “presence” slider works really funny: The opamps/gain they used make a lot of hiss noise, so they gradually enable this “presence” effect only when there is sound being played. This means that the “equalizer” is noisy only whenyou are playing and you perceive this “hiss” much less. I don’t know you but I never use the presence slider and this one is wired in parallel with the volume slider, so you can swap them, or swap the wires at CN12 (signal control), of course, in case the presence slider is not damaged too ๐Ÿ˜€ . I read you have a xp-50 with a serious issue, contact me and maybe we can sort out what the problem is. Groetjes, Hugo


  4. Hi Hugo,

    I’ve sold the XP-50 a little while ago as a ‘for parts’ unit. But thanks for the offer ๐Ÿ™‚ Thinking of doing the same with this JV-90.. I’ve allready spend way to much time on it and the reason I bought it is that I wanted a 76 key controller because playing piano parts on 61 keys is a little difficult sometimes. I’ve picked up a JV-1000 a few weeks ago that’s waiting to be fixed (red glue issue) and I like that a lot more than the JV-90. The JV-1000 looks very nice on the outside and this JV-90 has had a very hard life. So i’ll either fix it and sell it or don’t fix it and sell it in it’s current state ๐Ÿ™‚ But it’s definitely going.. I’ve already put about 15 euro’s worth of new parts in it and I found a new volume slider that will cost around 17 euro’s incl shipping. Maybe I can use the presence slider as a volume slider. I’ll look into that.

    I promised myself not to start on the JV-1000 before I fixed the JV-90 so I’m getting more and more eager to wrap it up and move on.


  5. Hi Jorick, excellent site. I have JV-90 too, having had it since purchased it brand new and enjoyed playing it because I like the touch of its keys. It was fun to play, until the keyboard was hit by a ball through by my son (at least that was the story I was told having happened, I wasn’t eye witness so don’t know the real truth). Now the problem is that set of buttons doesn’t lit any more and doesn’t seem to work: Two bottom rows of buttons in Edit paletta not working (top row seems to work and the sliders work too). Also bottom row of function buttons and whole patch group seems being dead. So I’m wondering if you might have any idea what is going on, as you have had your keyboard having been disassembled. I opened the cover but since the keybed seems being installed on top of the boards I run out of courage to uninstall anything more to see if any of the connectors between boards would be loosely connected; I was thinking that might be simple like that considering there is so many buttons dead.
    I was hoping the keyboard would get still new life if could be fixed as DYI, since it really is not dead since it is e.g. sending midi so it is still technically working though I can’t change patches etc.

    Greetings from Finland and happy new year 2016!
    Best Wishes Mika


    1. Hi Mika,

      I’ve looked at the pictures of my disassebled JV-90 and I think the only way to find out is open up your JV-90 ๐Ÿ™‚

      I think you can leave the keybed in the synth. Just remove the bottom plate and then remove the mainboard (lots of cables… take some pictures) The boards that have the problem are screwed to the upper metal frame of the synth and the connectors are on the top side.. so you’ll have to completely take it apart to check. Not very difficult but it will probably take the better part of an evening ๐Ÿ™‚ If you need more photos of my JV-90 I can send you those. If you want to look at the schematics of the JV-90 you can find them here:

      I hope it’s something simple as a loose connector.. The Edit Palet buttons and the Patch buttons are on 2 separate circuitsboards though.. so that should be 2 loose connectors then. These two circuitsboards are tightly attached to the chassis of the synthesizer so I can hardly imagine that the circuitsboards are broken or cracked. If an object hit your synth so hard I would probably have broken some of the pushbuttons on top as well.. just check all the cables.. maybe start with just disconnecting and reconnecting the ones on the mainboard before you take the whole thing apart..

      Good luck!



  6. It’s encouraging to see the work you’ve done to revitalize this JV-90. Gives me hope that I might find someone wanting to do the same with mine and put it to use again. For now unfortunately, it lives in a case in the closet as has for a while. I used to play it a lot and it had already been refurbished a bit when I bought it with new screen; however, some of the buttons for changing patches, changing tuning/transposition are no longer working (seems one at a time would fail over the years), which renders it impossible to use for my purposes any longer. It’s so sad to see it unused as at home and for events I’m currently stuck playing on a plasticky (yuck) Casio (a wonderfully welcome and needed gift but nothing compared to a nice Roland or Yamaha).

    Wish I could find a home for the JV-90 (and someone willing to repair the broken buttons), as I don’t have the time or ability to fix it myself and also don’t like seeing it just taking up space. They are such excellent synths, so nicely made with the metal body unlike many cheap keyboards and such these days. Do you have any ideas how much one should be offered for sale even with the needed button repairs (all keys and all else work perfectly as of the last time I played it)?


    1. Hi Amanda,

      I doesn’t cost a lot of money it you repair it yourself. The buttons that are broken are just 10 cent tact switches. Replacing them is quite a bit of work though. You would have to take the synthesizer completely apart to get to them. If you (or someone else) decides to repair it I would replace all the tact switches and not just the broken ones. Regarding the value: I’ve owned 3 JV-80’s, 1 JV-90 and a JV-1000 which I all repaired. They are nice synths but they are also 25 years old. In the Netherlands a fully working one fetches around โ‚ฌ150.. Usually I buy projects like these for +-โ‚ฌ50. I just had a look on eBay and there’s a broken JV-80 for $200 and a working one for $400. I doubt they sell for those asking prices but hey, it’s eBay ๐Ÿ™‚ having it repaired at a shop is not very economical given the amount of time it takes to repair one of these.

      If you have a steady hand and a soldering iron you can fix it yourself for a few dollars / euros ๐Ÿ™‚ or ask a friend..




  7. Hi Jorick
    I have the same problem with a JV90 I just bought – 4 switches no working.
    Trouble is I’m not sure how to remove the mother board. Is there a special technique for removing the cables from their sockets or is ti just brute strength and pull them out?


    1. Hi Rob,

      The black/white and red cables that have the brown or white connector at the end can be gently wiggled from their sockets by lifting the left and right sides with your nails or a small screwdriver. I can’t find any good pictures of the JV-90 mainboard but the black ribbon cables can also be gently pulled from their sockets. If I look at pictures I’ve taken from a XP-50 mainboard the white connectors soldered to the mainboard for those ribbon cables also have part that can be pulled upwards to remove the clamping pressure. Brute force is never required ๐Ÿ™‚

      Regards, Jorick


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