Memorymoog issue, help is needed.

[gencomprodukts]

Well, regarding the Hold function, both buttons (Hold and Mono) could be lit up when engaged but anyway, It's resolved now

Are you serious ? You also do have the same issue with the Arpeggiator ? We're damned lol ! I tried your trick with the midi cable but unfortunately there's no change.
I can only use the Arp with an external clock source (you too ?) and it's not the "clock in" jack, i've replaced with a new one but nothing's changed.
It's not the 3340 used as LFO, indeed i don't have any problems with the waveforms when i use the LFO section.
Do you really beleive i should reset the CPU ? Hahaha, no i won't, i'm too scared, frankly

Anyway, here is what i got from a very nice guy (Jareth from Synthpro) about this issue on the internet, maybe it could help :

Here is the signal flow for clock output to the digital board: Clock signal comes off the LFO through S21-3 on common analog and goes to S55-3 on DMUX, (DMUX is used as a jumper only from a ribbon to a wire so all passive).
The signal from S55-3 comes out of P517-1 to the clock Jack. When you plug a ext clock source in, it breaks the signal coming from P517-1 and feeds the ext signal from the jack to P42-5. Based on your symptoms you do not have any issues from the jack to the digital board but could be either a problem at S21 to S55 or from S55 to P517.

Take care

[Markyboard]

I forgot that your arpeggiator works with external clock- never mind the reset. Btw mine is working now, something from the midi input temporarily froze it but all is well now. I believe your problem is extremely simple; as Synthpro indicated you’re LFO clock is not getting to the input device on your Digital Board.

Let’s start with... can you tell me which part you used for the replacement jack? Part number would be good.

[gencomprodukts]

Thanks mark ! I also do beleive that the problem is relatively easy to resolve.
Unfortunatetly i don't have the part number for the jack socket. Reason is that to be precise i've replaced it with one that i took from an Boss Pedal but in both case it failled.
And some weeks ago i even put the original back with no success.
Maybe i could try to clean the 3340 (U22) on the common analog board as i did with the 3360 on the C&G ?

[Markyboard]

Hi Laurent-

Understood regarding the replacement jack. You need to confirm that you used a "switching" jack (also called a "shorting" or "shunt" jack). It has an extra contact that shorts a second signal to the tip when there's no plug in the jack. When you insert a plug it pushes that second signal away and you get what's coming in on the cable. These jacks looks exactly the same as a non-shorting jack (guitar jack) so that's why I asked.

Now assuming it's not the jack itself I still suspect it's a connection problem from the Common Analog (CA) Board to the Digital Board via the DMUX Board. But...the reason I say this is because you said your LFO is working. Please confirm that it is working on square wave both sound-wise and that you see the LED respond to the rate because this is also used as the internal clock for the arpeggiator. If it is working then no reason to mess with the 3340.

I never used the external clock input but I've had problems with the LFO because of wire connection issues. There was a factory modification years ago to the CA board that resulted in an extra transistor (Q5), a lifted resistor on one end (R187), a cut trace and an external wire soldered to the CA board. The wire is soldered to one end of that lifted resistor (R187). This is vulnerable to getting bumped and can be the source of your problem so take a look at these components and that soldered on wire. It may need some attention.

[gencomprodukts]

Hi Mark,
First i hope you're doing well
Thanks for all these informations !
Yes, i confirm that the Square wave LFO is working fine sound-wise and i can see the LED respond to the rate.
I already removed, cleaned the pins and re-seated the ribbon cables going from the CA board to the Digital but maybe i should try once again.
I do beleive i have this modification you are talking about, indeed, before getting sick my tech told me at the phone to check this extra resistor on the board (see picture included - Sorry for the bad quality) and the solder joint and everything seems to be clean

[Markyboard]

OK- that pic looks good as far as I can tell. And the lifted side of the resistor is what goes to the LFO LED so all good there. It's the other side of the resistor R187 that provides the clock output to the Digital board and I don' t think there's anything wrong there.

Re-seat the S21 connector on this CA board and also the S55 and P517 connectors on the DMUX. Take a look at the wire on pin 1 of that P517 connector, maybe push on it a bit into the connector while the arpeggiator is on and see if that results in any notes.

[gencomprodukts]

All right Mark, I'll do that asap and let u know. I hope that this will work, I cross my fingers.
Thanks.

[gencomprodukts]

Coming back with my report So i've tried everything but Unfortunately it didn't work out. I even cleaned once again the pins and sockets with Deoxit but nope, it doesn't seems to be a faulty ribbon cable.
P517 looks also perfect as well and pushing on the connector while the arpeggiator is on makes no results. I can only hear a constant/hold note when the arpeeggio is engaged.
Do you have any other idea ? Maybe there's something wrong with a chipset somewhere else.

[gencomprodukts]

I've seen on the schematics that the signal goes to P42 (pin 2) on the Digital Board and after a check i saw this. A wire is missing on pin 2. It's strange because there's no free wires into the MM+ but maybe i'm wrong. Is there only 4 soldered wires to P42 ?

[Markyboard]

Damn - I just lost my very lengthy reply ( maybe best)

There's not supposed to be a wire on pin 2 of P42 - I think you're looking at the wrong part of the schematic. N/C means No Connect so maybe that's where the confusion comes from But also know there are some errors on these schematics. However if you're looking at the left side of the DB schematic this has nothing really to do with the arpeggiator. Look at the top right where you see the External Clock label.

Nothing wrong with the "chipset". Otherwise the LFO wouldn't work. Trust me, it has to be a connection issue.

Is there anything plugged into the external clock when you're trying to use the internal clock? Just want to make sure. You're probably going to need a simple ohm meter (continuity meter). Just need something that buzzes indicating when there's a connection. Should be inexpensive.

[gencomprodukts]

Thanks for your answer Mark and ok for P42
Nope, no cable plugged into the clock in jack when i try to use the internal clock.
Unfortunately i think i'll give up for this issue, indeed we've tried almost everything.
Too bad...

[Markyboard]

Ackkkkk....NOOOOOOOO!!!

(Just kidding).

One thing you could try is connecting a clip lead from the CA board LFO directly to the shorting terminal of the external Jack. You’d have to purchase a mini clip lead but this would validate what I’m claiming. Once you do this we could go from there.

Or take a break for now- you’ve earned it. If you’d like send me a private message and we can exchange email addresses so you can get hold of me in the future.

-Mark

[gencomprodukts]

You right, i need a break. I'm too tired with this now but just to know, where should i exactly connect this clip lead on the Common analog board ? Could you please show me on the schematics or send a picture when you get time ? Thanks in advance !

P.s : I'll send you a private message