Sort of asked this before but situation changed after swapping main boards and a few questions in here hoping for some advice on. thanks in advance.
I have two broken JP-8000s.
First one I bought cheap as-is and was hoping it'd be a simple fix like replacing a slider/potometer - it was LFO'ing etc on it's own but not like ghost editing it was doing it at all time. I've done minor repairs before like replacing an MC-505 pot, replaced JP-8000 ribbon controller etc but I didn't mess with this synth and dropped it off at a reputable repair shop Three Wave Music in New Jersey, this was around 2014. He quoted ~$350 to fix. I said yes. Then he called a couple weeks later and said it'll cost more because it needs a board from Japan. I said no because the total cost would end up more than a %100 functioning JP I can get from eBay/Craigslist. I said I'll just take it back still broken, he said he still wanted to charge $350 for broken, we went back and forth for a bit and he ended up fixing it for the original price. I don't think he bought a board from japan but IDK. It worked fine for ~9 months and then it just bricked - it turns on but the screen lights up all solid pixels and there's no sound, Factory Reset he suggested didn't fix. We'll call this the "Bricked" one of the two.
I sorta tucked it away and bought another used JP-8000 which worked fine for a while but developed a common problem with JP8Ks because the main board capacitors are low quality and don't hold up to heat/hours which eventually causes low/distorted volume problem. We'll call this one "Low Volume". There's recapping kits on eBay with better caps for ~$35. But I'm told this era Japanese boards are notorious for lifting pads/traces when soldering and can ruin the main board which is ~$165 used on Syntaur but very rare and out of stock until who knows when. Despite there was no mention of lifting pads in the 2 recapping videos I saw. I also read 2 others on reddit ruined their main boards by lifting pads/traces and were looking to buy main boards. Even the well-experienced tech who worked on the first JP apparently had a bunch of pads lift hence the jumper wires he added, see pics below. Originally I thought these jumper wires were why the 1st one bricked but now I think something fried the motherboard processors etc. But it's still a mystery to me why the tech seemed to have resoldered all these connections to begin with which are all parameter knobs and sliders like LFO, portamento, etc - maybe due to ghost editing he replaced the pots/sliders w new ones and lifted pads in the process - maybe I can see when I disassemble the synth for parts. There seems to also be connections he resoldered successfully based on photos show orange flux or something compared to the pure silver color of the factory made solder points. One of these orange/flux areas is to a ribbon wire with many tiny solder connections as shown in 1 photo without a jumper wire in it. So, back to the JP which developed low volume (the second one I bought, not the one the tech worked on). I can mail out the main board and hopefully someone can recap it for ~$300, or maybe 3wave or another shop will do it.
In a previous thread it was suggested that the cause of why the first JP bricked could be from the jack board or power supply board and maybe not to do with the jumper wires the tech added. I've never heard of a JP-8000 with this problem though so maybe something the 3wave did caused this. Usually JP-8000s just ghost edit from dust getting into the pots/sliders or develop low/distorted volume from the low grade caps and that's about all I've seen, never seen one being sold for parts cheap on eBay etc with this type of problem.
A few days ago I swapped the main boards of these 2 JPs. The one that bricked didn't have low volume (bad caps) when it bricked, and I was hoping to get one %100 working plus also diagnose if the bricked one's main board is part of the problem. Well, the swap gave the other JP the same bricked problems so it's at least partly the main board from the bricked on is broken. Hopefully nothing fried in the process.
I probably won't risk putting my other main board (works but low volume) into the bricked JP because a faulty jack board/power supply could brick that main board too. But it's tempting because if it works (but just low volume) then I know the only problem was the main board (but why?) which I can wait to see if one ever comes back in stock, swap it and sell it %100 working (but with warning it may need recapping just like every other JP that hasn't been recapped). Or I can confidently part out the 'bricked' one knowing just the main board was the problem and not the jack/power board although I'd still give a warning and back story to potential buyers so they don't brick anything, maybe someone who's good with an oscilloscope, multimeters, etc can diagnose it without having to risk anything, if you think that's possible?
If I part out the bricked one now, minus the main board which I'll also try selling though with a warning, the only risky parts of the synth are probably just the jack/power boards and the other panels boards (with the jumper wires the tech added) IDK but maybe those aren't a risk? The keys, shell, joystick etc I can still get back a few hundred $. I'm not worried about the $ now just not sure the best approach for this and also just wondering what the heck went wrong? I could very well just go smash the two of these in the street and buy another without low volume and hope it lasts me without re-capping since it's not at all my main synth but is one that I can't let go of currently. Maybe even just sell the bricked one as-is with the fried main board to someone who knows what they're doing. The fried main board looks fine, not caps are swollen or anything, it was never dropped or high static use or humid etc IDK how but I guess the processor(s) fried.
Pics of jumper wires three wave added, there's many:
https://imgur.com/a/sPhNvCB
https://imgur.com/a/1hd6wL9
https://imgur.com/a/Se7L08A
https://imgur.com/a/KdMwFQP
https://imgur.com/a/aacXTfB
https://imgur.com/a/MfHunXX
https://imgur.com/a/oQaNF36
https://imgur.com/a/LAK3IYT
https://imgur.com/a/SfRmL8E
I have two broken JP-8000s.
First one I bought cheap as-is and was hoping it'd be a simple fix like replacing a slider/potometer - it was LFO'ing etc on it's own but not like ghost editing it was doing it at all time. I've done minor repairs before like replacing an MC-505 pot, replaced JP-8000 ribbon controller etc but I didn't mess with this synth and dropped it off at a reputable repair shop Three Wave Music in New Jersey, this was around 2014. He quoted ~$350 to fix. I said yes. Then he called a couple weeks later and said it'll cost more because it needs a board from Japan. I said no because the total cost would end up more than a %100 functioning JP I can get from eBay/Craigslist. I said I'll just take it back still broken, he said he still wanted to charge $350 for broken, we went back and forth for a bit and he ended up fixing it for the original price. I don't think he bought a board from japan but IDK. It worked fine for ~9 months and then it just bricked - it turns on but the screen lights up all solid pixels and there's no sound, Factory Reset he suggested didn't fix. We'll call this the "Bricked" one of the two.
I sorta tucked it away and bought another used JP-8000 which worked fine for a while but developed a common problem with JP8Ks because the main board capacitors are low quality and don't hold up to heat/hours which eventually causes low/distorted volume problem. We'll call this one "Low Volume". There's recapping kits on eBay with better caps for ~$35. But I'm told this era Japanese boards are notorious for lifting pads/traces when soldering and can ruin the main board which is ~$165 used on Syntaur but very rare and out of stock until who knows when. Despite there was no mention of lifting pads in the 2 recapping videos I saw. I also read 2 others on reddit ruined their main boards by lifting pads/traces and were looking to buy main boards. Even the well-experienced tech who worked on the first JP apparently had a bunch of pads lift hence the jumper wires he added, see pics below. Originally I thought these jumper wires were why the 1st one bricked but now I think something fried the motherboard processors etc. But it's still a mystery to me why the tech seemed to have resoldered all these connections to begin with which are all parameter knobs and sliders like LFO, portamento, etc - maybe due to ghost editing he replaced the pots/sliders w new ones and lifted pads in the process - maybe I can see when I disassemble the synth for parts. There seems to also be connections he resoldered successfully based on photos show orange flux or something compared to the pure silver color of the factory made solder points. One of these orange/flux areas is to a ribbon wire with many tiny solder connections as shown in 1 photo without a jumper wire in it. So, back to the JP which developed low volume (the second one I bought, not the one the tech worked on). I can mail out the main board and hopefully someone can recap it for ~$300, or maybe 3wave or another shop will do it.
In a previous thread it was suggested that the cause of why the first JP bricked could be from the jack board or power supply board and maybe not to do with the jumper wires the tech added. I've never heard of a JP-8000 with this problem though so maybe something the 3wave did caused this. Usually JP-8000s just ghost edit from dust getting into the pots/sliders or develop low/distorted volume from the low grade caps and that's about all I've seen, never seen one being sold for parts cheap on eBay etc with this type of problem.
A few days ago I swapped the main boards of these 2 JPs. The one that bricked didn't have low volume (bad caps) when it bricked, and I was hoping to get one %100 working plus also diagnose if the bricked one's main board is part of the problem. Well, the swap gave the other JP the same bricked problems so it's at least partly the main board from the bricked on is broken. Hopefully nothing fried in the process.
I probably won't risk putting my other main board (works but low volume) into the bricked JP because a faulty jack board/power supply could brick that main board too. But it's tempting because if it works (but just low volume) then I know the only problem was the main board (but why?) which I can wait to see if one ever comes back in stock, swap it and sell it %100 working (but with warning it may need recapping just like every other JP that hasn't been recapped). Or I can confidently part out the 'bricked' one knowing just the main board was the problem and not the jack/power board although I'd still give a warning and back story to potential buyers so they don't brick anything, maybe someone who's good with an oscilloscope, multimeters, etc can diagnose it without having to risk anything, if you think that's possible?
If I part out the bricked one now, minus the main board which I'll also try selling though with a warning, the only risky parts of the synth are probably just the jack/power boards and the other panels boards (with the jumper wires the tech added) IDK but maybe those aren't a risk? The keys, shell, joystick etc I can still get back a few hundred $. I'm not worried about the $ now just not sure the best approach for this and also just wondering what the heck went wrong? I could very well just go smash the two of these in the street and buy another without low volume and hope it lasts me without re-capping since it's not at all my main synth but is one that I can't let go of currently. Maybe even just sell the bricked one as-is with the fried main board to someone who knows what they're doing. The fried main board looks fine, not caps are swollen or anything, it was never dropped or high static use or humid etc IDK how but I guess the processor(s) fried.
Pics of jumper wires three wave added, there's many:
https://imgur.com/a/sPhNvCB
https://imgur.com/a/1hd6wL9
https://imgur.com/a/Se7L08A
https://imgur.com/a/KdMwFQP
https://imgur.com/a/aacXTfB
https://imgur.com/a/MfHunXX
https://imgur.com/a/oQaNF36
https://imgur.com/a/LAK3IYT
https://imgur.com/a/SfRmL8E
Statistics: Posted by bbing531 — Sun Dec 15, 2024 5:25 am — Replies 1 — Views 89