Roland JP-8000 Distorted Low Output and Repair

Roland JP-8000 Distorted Output
Roland JP-8000 Distorted Output

Recently I acquired a second Roland JP-8000 that actually was in like new condition, but it had a couple of output problems. The first was that the outputs L and R would no longer work, thus they were dead silent. In addition, the headphone jack would output a good signal but only up to level 6 or 7 and would then crackle or produce a loud distorted sound.

After some reading and research, I first changed the battery and did a memory reset. Nothing changed.

I then ordered and changed all of the OP AMPS on the Jack Board and Board B. Something changed! I now started to get output out of my L and R jacks but only to a level of 2 or 3. I also began getting some very bad distortion at higher levels that was very erratic. The OP AMP replacement seemed to have brought the jacks back to life but only to a point.

Thus I’m still faced with having a JP-8000 that doesn’t really produce any useable output. My next step is to replace the caps. I’ve read that replacing the caps on the Jack board didn’t fix much anything with others who had the same problem. However, I did find that if you change the caps on the Main Board, it does apparently fix the output distorted issue. I am now in search of the replacement caps as shown in the photo attached to the article.

It appears the Roland JP-8000 is one of those synths that is doomed to have some major failures as it ages. Not all synths are like this as some age better than others. I’d say pretty soon we’re going to see more Roland JP-8000 synths on the used market broken. Most likely they are going to have the distorted output problem. Note the JP-8080 rack version uses different caps and components than the JP-8000 which maybe is a hint that Roland knew the components used in the JP-8000 were not all that great. The Roland JP-8080 is pretty rock solid and I would recommend that over the JP-8000 if you are looking to invest in this particular synth.

In any event, once I make some progress on the Roland JP-8000, I’ll update this post. Also note that this again is my second Roland JP-8000. I have another in perfect working order which I may use to swap out boards to try and 100% isolate the problematic board. I did this with a couple of Roland Juno-2 synths I had which saved a huge amount of detective work. That certainly would help great in finding the problem with the distorted outputs on the JP-8000.

Stay tuned!!

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52 thoughts on “Roland JP-8000 Distorted Low Output and Repair

  1. Tony London

    Thanks for this Jim. I’ve got a JP-8000 which has odd output problems: really low levels on one output, and a buzz with the volume turned up.

    I’m thinking of buying a second unit because, as you say, this may be a major problem for a lot of JP-8000s.

    1. Yes, this is becoming a wide spread problem. What seems to be consistent is that one or both of the L(MONO) and R jacks have low volume output or are completely dead. The headphone jack usually works but in some cases the output can be distorted like mine. I believe that if the headphone jack has no distortion, then it will only be a matter of time.

      The only success stories I’ve heard with regards to this problem has to do with replacing the caps. I did find one solution by replacing the OP AMPS which I did to the entire JP-8000, but that only seemed to amplify the distorted problem. This makes sense and I think the caps are key. I’m just now trying to source the caps so I can replace them.

      Also, I’ve found that these JP-8000’s need to be played consistently or they are going to crap out by just sitting over time. I may pick up the JP-8080 as it’s much more stable and likely will not have the cap issues. If I can just crack the distortion problem though, I have a feeling I’m going to see a ton of JP-8000 synths dumped here in Japan for insanely low prices. The one I found here was just 1,000 yen or $10 USD because the sales guy felt it was completely unusable.

      Worse case scenario I thought I would either part it out and sell the JP or just use it as a midi controller for some soft synths. That would work well I think.

      Sure would like to fix the problem though. Thanks for the comments!

      Jim

  2. Tony London

    Jim/others – actually maybe you can tell me:

    Does your JP keybed feel plasticky and make a lot of noise when played?

    I’m talking about physical noise as the keys go down and up. I know all cheaper synth action keybeds make noise as you press keys, but I’ve got other synths and you have to hammer them pretty hard to get this level of noise.

    With my JP, let’s say I’m playing late at night with low volume. If I hit the keys at normal level, the sound of the keybed is louder than the music volume, unless I press the keys down extremely softly.

    Is that a JP-8000 problem? Or have I got a dodgy keyboard?

    I made a quick video of it. I’m playing the board with normal weight here. Is this noise normal?

    1. Hello Tony! My JP-8000 is also very noisy and feels plasticky like you mentioned. I haven’t yet checked out the keys, but sometimes you can add a strip of felt to dampen the noise a bit, but it may change the action slightly. Also, it may mean the grease could use replacing, although on mine I can see quite a bit inside there. The keybed is actually quite simple to remove compared to most other keyboards I’ve opened up. I’d say your keyboard is normal, but I’m sure you’ll see variations out there.

  3. Hi Jim,

    I’ve had the exact same problem with an XP-50. They also seem to self-destruct after about 20 year’s of service. I bought one that only produced a loud crackling noise through the outputs and headphones even when no keys where pressed. I’ve read a lot about these problems with the XP-50’s and I’m always in for a project so I gave it a try 🙂 I replaced all the caps on the mainboard but this didn’t solve anything unfortunately. I replaced the SMD caps for normal through-hole caps. A nice soldering exercise 🙂 I’m not an electronics expert so after I replaced the caps and that didn’t fix the problem I sold it as a for parts XP-50.. Here a link to my blog with some photo’s:

    https://synthsandkeyboards.wordpress.com/2015/05/06/roland-xp-50-music-workstation/

    grtz, Jorick

    1. Great info Jorick! Thank you very much. I think a couple of users including myself are going to tackle the cap replacement on the JP-8000. It’s seems 50/50 that it will work, but have to try. I’ll check out your blog. Have a great week!

  4. matt c

    i recently went thru this same problem. i replaced the caps on the jack board ad replaced one of the op amps. no change. i replaced the surface mount capacitors with nichicon caps. problem solved! i have full output now. i found a couple had leaked. i could not see the leaking caps until they were removed. i also replaced all the micro switches while i had it apart as some had to be pushed hard to get to work.

    1. Phil A

      Hi Matt,

      Where did you get the nichicon caps? Just be be clear, are they 16v 60uF surface mount caps? And did you replace the ones on the main board pictured in this article?

      Many thanks,

      Phil

      1. Phil A

        Found this thread relating to a similar problem on the Roland XP-50. Somebody verifies that the top number is the capacitor part number, the middle number is capacitance, and the lower number is of course voltage. In theory, these new capacitors I have coming should work. Will update when I’ve had a go at reinstalling them, and try and document some pictures. By the way, I’m ‘nismology’, the OP from this Gearslutz thread: https://www.gearslutz.com/board/electronic-music-instruments-electronic-music-production/868452-jp-8000-horrid-distortion-fault-help.html

  5. Thanks for the updates Phil. I just placed an order today for some 25V/10UF SMD capacitors. I’m pretty sure that should solve the problem barring any soldering errors…laugh. Since I’m out here in Japan, I ordered mine from China. They should get here within the next couple of weeks. I’ll keep everyone posted on when they arrive and how the installation goes.

  6. Phil A

    Progress! 😀

    I replaced all the capacitors in that section, and… no difference. Don’t bother. All the little 10uF 16v caps were ok. In my frustration, I started looking around at the other caps on the main board, and saw that there were two larger SMD caps next to Connector 3: C217 and C219. I noticed a tiny bit of corrosion on the solder joints of C219. In my curiosity, I unsoldered it, and sure enough, a pungent musty chemical smell, and behold, leakage underneath! I tested it with my multimeter, and it measured about 15uF, should have been 22uF.

    I had a rummage around, and found an ancient old floppy disk drive that I had lying about. I found a 47uF SMD cap inside (this thing’s about 5 years older than the JP). I transplanted it into the place of the bad cap I’d just removed from the JP.

    I put it all back together, and after about 10 secs of distortion and low output, it roared into life! Full volume on the headphones, and no distortion! The L/R outs were back too, albeit about half the volume of the headphones, but I think this is normal for the JP (?) I reckon that cap was the problem! Unfortunately,a couple of mins later, it stared to get a bit crackly and lo-fi sounding, not the same as before, but I reckon that’s because it’s a musty old cap I used. I’ve ordered 10 brand new SMD 16v 22uF caps from eBay, and paid for 1st class postage, so hopefully I can finish the job on my day off on Friday!

    Will keep you posted.

    For reference, this is the replacement cap I’ve ordered:
    http://www.ebay.co.uk/itm/261820404834?_trksid=p2057872.m2749.l2649&var=560679749420&ssPageName=STRK%3AMEBIDX%3AIT

    Select ’16v 22uF’ from the drop-down menu.

    Pic: https://flic.kr/p/EAkMgf

    1. Thanks for the update Phil. Geez, I ordered my caps a while back and still haven’t received them. Perhaps I won’t need them after all. I’ll probably replace the 22uF ones first as you seemed to have indicated they might be the bad boys. Thanks again – Jim

    2. Max

      Thanks PHIL Got the cap in a bunch of 10 did the solder job and I now have my JP 8000 back up and running. Cheers for the link. All the best.

  7. Hi Jim, Many thanks for hosting this forum on your site it has been very helpful. I have experienced exactly the same issues with low volume and distortion and was gutted as I love my JP8000. I replaced all the through hole capacitors on the output board with no real improvement. I also had spare op amps but as one of the ones I was going to change was next to the volume control I left these after reading this thread. I decided to change C219 and bought a few SM 22uf 16V replacements. They were quite cheap, I got ten for about a pound. After carefully desoldering the original and replacing it I am glad to confirm it has fixed all the issues I was having 100%. The synth has never sounded better, very punchy and plenty of volume. In my view C219 was 100% to blame for the issues I was experiencing. I don’t think the change of caps on my output board did anything sound wise but it won’t have done any harm.

    So in a nut shell, special thanks to Matt C and Phil A for your work. Matt for changing the caps in the first place and Phil for narrowing it down to C219. I also got the weird smell when taking this component off the board. I cleaned the board with a Q tip before replacing the capacitor. It was quite fiddly, and the new one was ever so slightly smaller which did help a little. Just be careful with your soldering iron as you are right next to the white connector for the PSU wires. Use a small tip soldering iron and don’t have it too hot. Easier to turn it up a bit than lift the track. I just applied a bit of new solder to each pad first then used some long nosed pliers to gently remove each side when the pad heated up. I also used a bit of flux when soldering. So to all the people with this issue C219 is one that will need replacing if you have these issues. This repair is really only for people who are confident at soldering. If your not get an expert to do it. Now we know the most likely cause, don’t kill you JP8000 with bad soldering.

    Kind regards

    Tony K

  8. Thanks very much Tony for the update. I just ordered some caps to replace the C219 and will be able to update you all shortly how I fair on this as well. My other smaller caps finally came for the main board, but will hold off on those until I replace the C219 one. Here is a photo of my JP-8000 main board showing the section that contains the C219 cap that we are all talking about for reference in case anyone wants to see what it looks like.

    The infamous C219 cap that caused Roland JP-8000 synth distorted output. Replace that puppy!

    A post shared by Jim Atwood in Japan (@jimatwood) on

    By the way Tony, did you replace C219 with the exact same cap, or did you purchase ones with legs? Just curious how you did yours. I ordered both actually.

    Thanks again!

    Jim

  9. Today I replaced the C219 cap with a new one opting to use a capacitor with legs.

    PERFECT!

    The Roland JP-8000 roared back to life and with the OP amps changed seems to be a tad bit stronger than before. The C219 cap indeed appears to be the problem.

    THANKS TO EVERYONE! for the help and I think this problem is finally solved. No doubt future JP-8000 synths may experience this same problem, so it’s great that we can keep it alive.

  10. Hi Jim, That’s great news and as you say pretty much confirms this capacitor will more than likely fail in all of these synths. Fortunately due to it’s small size it doesn’t appear to have the ability to cause too much damage to the PCB. At least that appears to be the case in the short term. To answer your question I did use the same SM style capacitor as the original but a different make. Clearly using one with legs does the trick as well so that is an equally viable option. Anyway as you say thanks to everyone, a good team effort and a few more of these precious synths stay functional into the future. Very best wishes. ;o)

  11. juanma71

    Great site and nice repair too.

    I need spare parts for my JP8000. In fact, the Panel Board A is cracked and need to replace it. Do you know where can I find this kind of parts?

    Regards.

  12. Dear Jim,
    I find your page in a search.
    I just bought a second hand Fantom G7. I connected it directly to the mixer. It worked very well 5-10 min, than very noisy shocks, and the sound disappear. I tried every output audio, and no one works. I friend told me now that maybe need a Di-box.
    Do you know how repair the Fantom?
    Do you know if it really need a DI-box for working, or the problem can be other?
    Sorry for my bad English because i´m portuguese.
    Best regards

  13. Matt C

    Hey guys, sorry I have not been back in a while. I know answering your question is probably irrelevant, but I purchase all my electronic parts from Mouser.

  14. ace

    With regard to the noisy keybed: these keys rely on proper lubrication. The grease that was applied almost 20 years, had dried out and hardened. Yesterday I opened up my own JP8000, I cleaned the keybed and I applied a new layer of silicone grease: not only does the keybed operates a lot smoother, it has also become quite a bit quieter.

  15. synthy

    Hi Jim and anyone else reading that may be able to help,

    Just turned on my JP8000 that I haven’t turned on for a few years and there is no signal on the main L/R output. It was working before. The headphones out are OK, no distortion or volume drop and works with the volume knob no problem. I am thinking of doing the C219 change hoping it will fix the main output issues.

    I have a couple of questions to you or anyone who may be able to help.
    – Is the C219 likely the common issue for the no mains output?
    – I noticed you replaced the C219 with a different cap from the original surface mount. What sort of cap is acceptable? film, tantalum, ceramic, mica?
    – Does the C219 cap have polarity?
    – How easy is it to access this main board where the C219 is? Are there any instructions anywhere that show how to dismantle the unit to access it that you could recommend or provide?

    Thank you.

    1. Antti Huovilainen

      C219 is part of the output mute control circuit. From what I can see in the service manual, you should be able to leave it out (disabling the mute) or replace with any capacitor between 1uF – 50uF as long as the voltage rating is 16V or more.

      That said, the mute control circuit controls muting for all outputs (main & headphone). If the headphone output is fine, then I’d check main output mute transistors Q1 & Q4. The headphone output is tapped after main output dc-blocking caps, so everything up to that should be fine. If you have a multimeter, check voltage at CN1 pin 2. It should be around -15V if the mute control is fine.

  16. xavier capdevila

    Hola, me alegra haber encontrado este post porque de leer vuestros comentarios y por mi problema con el jp8000 de no tener audio en L y R pero si en auriculares pero bajo de volumen y forzar al maximo con distorsiones a cambiando el c219 en la placa principal componente con valor (67 22mf 16v) capacitor……i funciona 100%

    Muchissimas gracias!!!!!

  17. Max

    Hi Jim

    In that shot of The infamous C219 cap. Is the cap in question the one with the following numbers on it? 68/22 16 V. I have ok headphone out but very distorted main outs so I will try this fix.
    Thanks a lot for your post, I have only had the JP 8000 for two weeks and boom.

    1. Of the top of my head, I’m unsure. I’m not at my synth or photos, but I can say my headphone out worked fine before the operation. I just wasn’t getting any L/R output. Now all is fine with that cap change.

      1. Max

        Alright then I have the board out now so I will go for the transplant. Let you know how I get on down here in NZ….all the best

  18. Max A Million

    Hey Jim
    I replaced the cap 219 based on this awesome forum. Took a bit of confidence to attempt a SMD solder job for a novice but it has been very successful. Booted up no problem and had great levels and zero distortion. Got the cap from the suggested Ebay seller here for about 10 bucks for a strip of 10. Thank you very much for this information you provided here….gold. All the best. https://www.youtube.com/watch?v=VaSUwHbAopk

  19. scottrod

    It looks like the reason these fail is the circuit is running at 15 volts and it’s a 16 VDC limit cap. That’s pretty darn aggressive given build tolerances and age.. Best to replace it with a cap having the next size up voltage rating.

    The Panasonic EEE-HA1E220WR is a good choice. It is the right 5mm diameter size and is rated 22 uF @ 25 VDC and 105 °C. Should last forever.

    1. JamesTB

      Hi Jim et al,

      Thanks so much for all the hard work. I’ve replaced the cap and it’s now working perfectly again.

      Two questions:

      First, when those who replaced the op amps fired them up again, did you notice any difference in sound and is it worth me replacing them?

      Second, Scottrod, I was thinking the same thing as I’ve seen pa amps do the same thing to capacitors when spec’d to close to their tolerance. How has your mod gone and has it made any negative differences in the function before I strip the 16v cap out and replace again?

      So glad we’ve all got working JPs again 🙂 Good work Jim.

  20. scottrod

    @JamesTB|

    I haven’t had any issues with the new cap as specified in the C219 position, would do it again. I wouldn’t replace it a second time if it’s working fine though, you can always make things worse!

    Best –

    Scott

  21. Micxter

    Hi all,

    I had the exact same issue with my old JP8000 (low distorted volume). I decided to give it a shot and replace C219. I ordered a surface mount (SMD) 22uF/16V capacitor from Mouser.com. Replaced C219, then I fired up the machine, It sounded really bad for 5 seconds, then it came back to life. Loud and clear. This is the best $0.50 fix. Thanks for the tip.

    Micxter

  22. Jukezz

    Hello all!
    I just got me JP8000.
    Just one MINOR problem, so to speak: The LCD screen (display) is not working at all… ;(
    Is it a hard task to replace? Where to get a spare part??? Help needed!!

  23. Jukezz

    Thankz JamesTB for your reply. Did you mean that OLED display?
    Has anyone placed a HD44780 LCD screen on it?

    Can you please tell shortly what does it need to do when replacing the display…
    There is a video on Utube about battery change… the same way underway to the task?

    1. JamesTB

      Hi Jukezz, sorry I was a bit pressed for time.

      So, the link below is for an original. There was another one available the other day but that’s gone now. The oled is blue. I think it’s quite cool and I am currently refurbing my 8000, but I want a red display. I’m trying to source one from Winstar (I think they made the WE-A displays).

      Having gutted my synth I can tell you they are very easy to take out and refit but you have to take a few boards out to get to the display. If you have any experience with electronics then you’ll be fine but otherwise I wouldn’t recommend taking bits out of it as replacing stuff can be a pain. Totally up to you though.

      If I can source the right display for my new look 8000 then I’ll message you to see if you still want my old one. Works perfectly 😉

      Good luck.

      http://m.ebay.co.uk/itm/ROLAND-JP-8000-JP-8080-DISPLAY-PERFECT-WORKING-CONDITION-/232161951441?nav=SEARCH

      1. Jukezz

        I’m out of the trouble now! Eventually all works perfectly. Still a little concern, if it will be ok on the road!!!
        I have no case for it at the moment. Folks, hard box or a soft case, what would you prefer?
        Well…to answer myself…hard box would be best, but are a bit pricey…

  24. Andy

    Hi,

    I have the same issue with my JP8000, one main completely dead, the other has a ridiculously distorted low output, and the headphone out is distorted as well, but there is output.

    So exactly which caps do I need to replace? Only the C219? I have the memory error as well, in case that’s related. The unit has been unused for the past 4 years. I would be very thankful for help.

  25. JamesTB

    I’ve messaged Roland support but I’m not sure they will help much as the JP8000 is so old, but, does anyone know how I can electronically test the keyboard? I am getting positive results from the system test for waves formed by the oscillator (1?) but no keys are working to produce sounds or midi signals.

    Thanks,

    James

    1. Hi James,

      Can you get sound out of the JP-8000 if you connect another keyboard/controller to the midi-in port? Check if the MIDI setting ‘Local’ is set to ‘ON’. If it’s ‘OFF’ the JP-8000 won’t produce any sound when you play the keys.

      Regards, Jorick

  26. Hi Jim,

    I have an owned a Roland JP-8000 keyboard for a number of years. I bought the unit new when I was visiting Tokyo many years ago. As the unit is from Japan it runs from the local power supply of 110v. Unfortunately when I bought the unit over to Hong Kong a few years later I believe the keyboard was mistakenly put into the local power supply of 220v without a transformer and some damage was done to the keyboard.

    I now live in Singapore and a few weeks ago gave the keyboard in for repair to a large music retail store who are the official Roland distributors here. Unfortunately they have now told me that the power board/supply in the keyboard needs to be replaced but they cannot do this as the parts are no longer available. I googled around a little and found your website. Would you by any chance know where I might find a power supply board for this model? Maybe Japan/Tokyo has more retailers of these parts than where I am…. I would love to get this synth working again!

    Any help would be much appreciated.

    Best regards,
    Rick

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