JP 8000 Battery Low

Forum for JP-8000/8080 synthesizers from 1990's
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dubmecrazy
Posts: 1
Joined: 19:32, 24 March 2011

JP 8000 Battery Low

Post by dubmecrazy »

Hey all. My beloved JP 8000 is getting a battery low warning, so clearly I need to change the battery. Before I do this, however, I need to do a dump in order to save all my user patches I've created over the years. However, my MIDI out doesn't appear to be working. I'm able to receive data (like clock date, e.g.) but I get nothing for MIDI out. I've checked the settings in the menu, I've plugged it into multiple devices set to receive data - nothing. I've tried cables, etc. So...my question is, is this any kind of known issue? Would the battery low have anything to do with MIDI send? Could these be related? Or is my MIDI output hardware fried and I need to replace it? Second, does anyone have any recommendations for changing the battery? I've read some stories online where users lose data - I cannot have this happen when I replace the battery, so any suggestions appreciated. Thanks so much.
fox69
Posts: 2
Joined: 16:18, 12 April 2011

Re: JP 8000 Battery Low

Post by fox69 »

Dunno if you still need to find this out, but my JP-8000 midi out just died, so I'll replace the battery tomorrow and see if that restores its MIDI out. Not gonna lose any programs so its no drama for me.
fox69
Posts: 2
Joined: 16:18, 12 April 2011

Re: JP 8000 Battery Low

Post by fox69 »

Looks like the issues are related - low battery on a JP-8000 may stop the MIDI out from transmitting.

I replaced the battery in my JP-8000, switched it on, MIDI was working but the display showed the Memory Damaged! error, so I reset to the factory settings. Everything appears OK now, but I haven't tried anything much out to be 100% sure nothing went astray.

Also FYI I used an anti-static wrist strap and clipped it to the metal shield near the power supply. Obviously you turn the synth off and have everything unplugged, and it's also a good idea to leave it off and unplugged overnight so the capacitors can discharge before you open it up. Use insulated screwdrivers and don't touch anything you don't need to touch. A wrist strap and insulated screwdrivers are cheap, so you may as well get them.

I attached a few pics of inside the synth. In one you can just see the battery holder under the metal shielding. In the other pic the 10 or so screws to remove are marked in red. Removing the one on the far left means you can tilt the shield up out of the way without the cables getting in the way so much.

The bad news is that it looks pretty tricky to swap the battery without losing your patches/performances. It could be possible to use jumpers to connect a fresh battery on to the contacts underneath the battery holder while swapping the battery out, but you'd have double voltage on the circuit for a short time which could damage something. Personally I'd find a tech.

Hope this helps.
Attachments
Screws to remove to access battery in JP-8000.
Screws to remove to access battery in JP-8000.
jp-8000-battery2.png (255.3 KiB) Viewed 3507 times
Location of CR2032 battery in JP-8000
Location of CR2032 battery in JP-8000
jp-8000-battery1.png (280.35 KiB) Viewed 3507 times
realtrance
Posts: 128
Joined: 16:39, 8 April 2005

Re: JP 8000 Battery Low

Post by realtrance »

The memory damaged error shows up when you've swapped out a battery; it shouldn't be an issue.

You should, however, recalibrate the joystick and ribbon controller. Roland may still have service manuals to sell that walk you through diagnostic and calibration modes; if not, there are some posts on how-to you can find searching here, or using Google.
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