JP8000 problem with jumpy parameters

Forum for JP-8000/8080 synthesizers from 1990's

JP8000 problem with jumpy parameters

Postby databaze » 19:31, 16 July 2012

So I did do a search regarding this issue and many people seem to point to cleaning sliders and knobs with something like DeoxIT FaderLub.
My questions is: The parameters change when I press on the keyboard case, not the knobs, not the sliders, not the keys, just the outside of the keyboard, now, I did use shift/exit to see what parameters changed and it seems like many of them do randomly depending on where i put pressure.

Anyway, I just thought i would ask if anyone had solve their problem completely by contact cleaning every single slider/knob in the unit of did anyone had to take it to a shop to get it checked out?

Thank you!
Posts: 2
Joined: 19:25, 16 July 2012

Re: JP8000 problem with jumpy parameters

Postby databaze » 04:26, 22 November 2012

After months and moths of having this synth sitting in my studio with the same problem and me not needing it to work, I decided to try and fix it.

I read on some other forums about using Deoxit F5 to clean the faders and knobs, then Deoxit 100 to lub them up so I did.

Same problem reappeared after one day of using it. I decided to track each parameter that changed when i pressed on the case or played the keys too hard, then I took the Board A out (the one on the left side when you have the synth opened) and I noticed that if I moved some of the knobs, the soldering of the 3 pron connector was loose.

Yup, all this time, and I did not notice it, the only reason I did noticed this time: Putting the board right next to my eyes, and then confirming it using a magnifying glass.

Now I just need to remove the old soldering and voila, hopefully it will be all over and I will have my JP 8000 back in the game!

It was a very hard trace, more so when you don't have all the tools needed to test each connection to the board, etc. I plan on buying all the equipment since I really want to get into fixing my own gear.

If anyone else is having this issue, you know where to look now other than dirty contacts on faders and knobs!

Posts: 2
Joined: 19:25, 16 July 2012

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