juno 66 install problems

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asclepias
Learning to Wiggle
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juno 66 install problems

Post by asclepias »

I am having some issues after Juno 66 upgrade. Before I installed it the pwm did not function. Everything else worked great.

After upgrade there was initially two problems.

1. when i pushed arp button all sounds stopped and i could not get any sounds in any play mode while arp button engaged
2. every 8th key starting with left most d (range lever set in middle) sounded different and sometimes arppegiated, or pulsed.

After removing cpu board to double check soldering and then quickly resoldered each pin the problem with every 8th key changed. Every 8 key stopped sounding at all rather than making a different sound. Arp still didnt work.

I removed cpu again and checked continuity at each pin to the appropriate place on board, resoldering again

now sound is unpredictable barely controllable in each play mode . sounds stay constant like hold is on. env not behaving as it should arp sometimes makes sounds. every 8 key either doesnt work or it makes a different odd sound. key transpose no longer lights up, can not get into configure mode (lights never blink) its in a pretty sad state right now

i have a new cpu chip on the way, the old one got damaged while removing it.

i have seen a post somewhere on here with someone having a very similar problem that seemed to progress in the same way.

hoping someone can help.
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tubbutec
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Re: juno 66 install problems

Post by tubbutec »

Hi,
please contact us directly: support (at) tubbutec . de
Cheers
T
asclepias
Learning to Wiggle
Posts: 3
Joined: Sat Jul 23, 2022 7:10 pm

Re: juno 66 install problems

Post by asclepias »

New chip hasn’t arrived yet.

But have realized part of the issue has to due with cpu pin 29 and p12 (port 1 #2). It reads 3+v all the time no matter what key is pressed.

D1 A#1 F#2 D3 A#3 F#4 in this patter every 8th key all the way up. Its like the note is stuck being sent through.

I can make the sound go away by sending midi signal. Midi plays these notes just fine.

Continuity checks out at all the appropriate places. I have scanned the bottom and top of the board with magnifying glass and lightbacklight looking for bad joints broken traces but have not found anything. Power at pin 40, and 26 is 4.92v

All the play modes do not function as they initially did. In one mode when i press a key i have to hit it twice before it sounds. (Even when its a midi signal). This happens with every key (except the ones that don’t work).
In another play mode sections of the keyboard dont sound while others do.

The key transpose issue was the associated led with a bad connection.

Im still looking for clarity about old arp issues and needing an update to fix them. I am not sure if this could have been the arp problem.

I am pretty sure this was an installation issue rather than an issue with the hardware!

I also discovered On the bender board I connected the free leg(not the one sharing pad with resistor) of the capacitor one pad to far to the right. This caused the vcf slider to affect filter without moving the bender. This happened AFTER original issue. Hoping it didn’t cause the other issues that have shown up.

Also I do have an oscilloscope and am ready to use it if anyone has time to help me troubleshoot this.
asclepias
Learning to Wiggle
Posts: 3
Joined: Sat Jul 23, 2022 7:10 pm

Re: juno 66 install problems

Post by asclepias »

Problem solved!!!

I would love to say it was my incredible electrical engineering sleuthing skills that figured this out but that would be a lie.

I revisited pin 29 on cpu chip with soldering gun and it resolved the every eighth key problem.

So for the third time I touched up my solder job on all cpu socket pins. I also went over ic 57 because the heat gun softened solder on one pin during cpu removal.

All issues are resolved. Everything is working and sounding great!!!

Now I just need to fix pwm, but thats for another post another day...

Thanks Tobias!
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