ROLAND JX3P (1983) sequencer issues

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Hi this is my first post here
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Thought I might finally make an account and try and figure out this problem I've been having with my jx3p.

I'm having a problem where the sequencer wont play a full sequence, just the first note or just the first few notes of the sequence together as a chord even though I play the notes in the sequence apart.

Sometimes the LEDs in the silver square buttons also come and go or even flicker on and off, the sound bank or patch of the button pressed still changes and makes sound however, so thinking it's not a battery issue?

I'm not sure if these issues are interrelated but they started happening around the same time. The jx3p still has all its voices and sound great, selects patches etc. . . to be clear I've just I've got no sequencer and random lights coming and going on the buttons themselves.

I'm pretty handy with soldering iron so popped it open but I can't see any obvious damage anywhere. I'm thinking I will replace the battery and fuses but not sure this will change anything as it seems to have no problems storing my patches.

I've found some good quality schematics here: http://www.florian-anwander.de/roland_j ... _schem.htm

Any ideas on where to start looking?

Thanks for the help!
 
Well the problem seems to have gotten worse.

Now occasionally it will go for working, to working without the sequencer operating properly. To not working at all, making a noise as though every key was been played simultaneously and all LEDs lighting up.

I've checked the battery which is good. Checked the fuses. Checked the mains power and have also checked the power supply which seems to be putting out the correct voltages. So i've covered the basics.

I've tapped around with a wooden rod to see if there were any glitches or bad solder joints that might reveal themselves. No luck.

What seems strange to me now is how the synth can go from working to everything gone haywire back to working again.

What does it generally mean when it sounds like every note is being played and all the LEDs are coming on simultaneously?

Is there anything I could test in particular with my multimeter to narrow things down a little here? I'm alright with a soldering iron but this synth is really complicated internally. Hoping somebody with more experience might be able to get me started diagnosing this issue.

Thanks
 
Sorry forgot to mention that I have re-seated the connections already Nigel. I did resolder one particularly bad looking joint that seemed like it had been repaired in the past but I guess I'll go through and reflow everything that looks suspect. Though I'm not too sure how picky I should be about this?

Enzo, when the sequencer was not working correctly I have the PG200 programmer plugged in. The jx3p allows you to select between receiving/sending midi and using the pg200 programmer but will not allow you to use both simultaneously. The programmer and midi in/out use different ports however. Does this help?
 
MIDI can sometimes confuse issues. Shouldn't the sequencer operate with nothing else? Isn't it an internal feature? Point being if we can sequence on the synth alone, there might be a MIDI conflict when it can't work with another device involved.

I have forgotten a lot of my keyboard chops, but if handshaking is turned on when you don't intend it to be, the system might be waiting for a communication it never gets. That is a made up example, just for the idea. Even something as simple as a MIDI address that got itself changed.

So many keyboards came in over the years needing nothing more than reinitialization, lead me to always look down that path first. All it takes is one bit in memory changing and the whole system can be confused.
 
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