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JP8080 acting unpredictably - any suggestions?

Posted: Sat Nov 19, 2016 6:13 am
by Eschatelan
Hi, I'm new to the forum, and not a synth expert.

My beloved JP8080 is acting very unpredictably - sometimes you load a patch or performance (a performance meaning you toggle the patch/perform button) and it works ok, sometimes you have to switch it off and on a few times before it will load the patch or performance properly. When a patch or performance doesn't load properly it will do weird things like sound totally different with the wrong envelope settings for filters and amp. Sometimes switching to another patch or performance and then back again fixes the problem, sometimes you have to switch it off and on repeatedly.

Any suggestions? I am wondering if a new battery would help?

Re: JP8080 acting unpredictably - any suggestions?

Posted: Sat Nov 19, 2016 9:21 am
by Broadwave
Eschatelan wrote:
Any suggestions? I am wondering if a new battery would help?
That would be the first thing to look at - I had the same problem with my old JP8000, a new battery fixed it.

Just remember to dump your patch sysex data first ;)

Re: JP8080 acting unpredictably - any suggestions?

Posted: Sun Nov 20, 2016 10:59 pm
by Eschatelan
Broadwave wrote:
Eschatelan wrote:
Any suggestions? I am wondering if a new battery would help?
That would be the first thing to look at - I had the same problem with my old JP8000, a new battery fixed it.

Just remember to dump your patch sysex data first ;)
Many thanks!

Re: JP8080 acting unpredictably - any suggestions?

Posted: Mon Nov 21, 2016 12:20 am
by dawnmist studio
Hiy

I have had my own JP8080 second-hand for about 6 years and it was fine until about a month ago. Then it began to develop weird sounds within the sounds that I normally play. I thought they were being caused by old wires in the studio but eventually tracked it down to being the JP8080 itself...

Upon further inspection I realized that by using white noise and turning off certain other features I pinned the weird sounds down to something going wrong within the make-up of the actual sound itself, some sort of fault, like the code got corrupted. When using white noise only I get a weird distorted sound that is intermittent a bit like a morse-code sound or a crackling sound but it was concentrated on a pitch matching A#.
I uploaded to Youtube this white noise fault sound:

After that I got someone I know who is an experienced electronics engineer to look at it. The battery was checked and was reading the correct voltage. Several chips around the battery were checked to see what voltage they had but were fine. Various plugs and sockets were wiggled. The unit was put back together and was fine for several days then developed the fault again, only this time not on the white noise but on some of the bass sounds I was using which revealed weird intermittent behaviour in the pitch and portamento department! :-(

I had done a factory restore after the battery and wires were checked but it is now doing it again.
It seems that the fault occurs about 1 - 2 hours after the unit being used so its like it warms up then it occurs.

On the www I searched various articles and a lot of people have been finding that capacitors seem to be top on the list for faults. Some say they can sometimes leak, sometimes problems occur but are not always visible. I am still looking for a solution to this problem now as of writing. Having my JP8080 faulty is like loosing a 5th sense, like loosing my way in this world, like loosing house or car keys, or having loosing the use of an arm or leg, sob sob sob.
I bought a JP8000 last week as I had been planning to have one anyway but I want my JP8080 working again!

Roland do not repair old units anymore, just items under warranty that are newer. They were helpful and gave me a phone number of someone in my region (60 miles away in Tavistock, UK) who repairs music equipment. I might have to contact them. So if you discover what the problem was let me know by e-mail: heather@dawnmist.org

Thanks.

Re: JP8080 acting unpredictably - any suggestions?

Posted: Mon Nov 21, 2016 5:40 pm
by Zamise
It has been a while since I had one, but I remember them having issues with ghost edits. You could see parms changing by themselves, like the sliders would get overly touchy to a breeze or vibrations. Not sure if it is the same thing happening with either of yours, but if I recall correctly a firmware update they supposedly put out helped stop that from happening on it. Even if that isn't it, probably wouldn't hurt to make sure you have the latest firmware installed on your JP 80x0.

Re: JP8080 acting unpredictably - any suggestions?

Posted: Tue Nov 29, 2016 3:07 am
by synthRodriguez
If you're getting nasty sounds, for the JP-8000 replace capacitor C219 with a Panasonic p/n EEE-HA1E220WR.

I can repair it here in Ohio if interested. Not familiar with the ghost edit issue, but sounds pretty easy to fix as well.

Re: JP8080 acting unpredictably - any suggestions?

Posted: Thu Jan 19, 2017 1:18 am
by DX
If an asterisc is shown on the LCD when the weird sounds come, it means a slider or knob has read a value change, so it affects the sound. Set the Midi Analyzer on (or Scope, don't recall how is it named on the JP now) and it will show which control is being changed in realtime.

Re: JP8080 acting unpredictably - any suggestions?

Posted: Thu Apr 13, 2017 5:09 am
by dawnmist studio
Update April 2017. Still not fixed but I am fairly sure now it is a capacitor problem and have been given block diagrams. Am hoping to get friend to change the suspect one's one by one.

Re: JP8080 acting unpredictably - any suggestions?

Posted: Wed Jun 20, 2018 10:04 pm
by Eschatelan
Two years later and the JP8080 may need it's battery changed again - does anyone know does it help the battery life if I leave it plugged in (not switched on, just plugged in)?

Re: JP8080 acting unpredictably - any suggestions?

Posted: Mon Jun 25, 2018 7:14 am
by ItsMeOnly
Eschatelan wrote:Two years later and the JP8080 may need it's battery changed again - does anyone know does it help the battery life if I leave it plugged in (not switched on, just plugged in)?
If that's an ordinary CR2032 or similar, barely. This device isn't a soft-on/standby machine, so it won't make a difference. What will make a (small, but confirmed) difference is powering the synth on every few days/weeks and having it run for a while.