I’m experiencing a common vintage synth problem on my Memorymoog plus and would really appreciate any advice you can give me before I attempt to repair it.
Here’s the problem: I noticed that the same 3 key are not working on every other octave. However, when triggered through midi all notes play fine.
When I press the auto tune button it says 6 tuned so I’m thinking it’s a contact/connection problem and not a voice issue???
I was going to follow the link below and and clean the keyboard contacts.
Your voicecards are fine. Something is wonky in the keyboard system. You can try the cleaning on that webpage (I wrote that page) but if it doesn’t work then something is wrong with the circuit.
The best way to repair the panasonic keys contacts is to use Caikote 44. My MM+ had several malfuncting keys (bad contacts on some keys or no contacts at all) and everthing works fine now. Caikote 44 is very easy to use and it’s very cheap. A perfect tool, i higly recommand.
If every sixth key is missing anywhere you play on the keyboard, the problem is not the keyboard.
You can find a service manual online that will help diagnose which voice is problematic. You can also disable the faulty voice card, once you determine which one it is.
Well, maybe i’m wrong but i don’t realy think it’s a faulty voice card since everything works fine when triggering with an external midi keyboard (see the first post) and the system controller says 6 tuned after the auto-tune routine so i suggest to check first the Kbd contacts then the Kybd Ribbon cable (i’ve already had the same issue and it was the ribbon cable socket).
Sorry, I should have made it clear I was addressing JJJ s problem in 2015, missing every sixth note, not the original poster in 2012. My comment stands.
2.There`s a buss bar for data lines connected whith the keybed. Check this and all connectors carefully.
3.There`s a cable leaded from the keybed to the digital board and plugged into P48B . Check pin 6 from the cable (white/blue) = data line 6. Check this very carefully. Now continue to go on checking the printed circuit leading to the IC: U28, pin 15.
The following should be done ONLY if you`re very courageous !!!
On the digital board there are two plugs that are connected with the keybed: P48A (pin1) and P48B (pin 6)
Try now, VERY CAREFULLY !!! NEVER TOUCH TWO PINS AT THE SAME TIME !!! to connect the pin one from P48A with P48B pin 6, the Instrument must be switched on for this action. When you succeed to connect these both pins and you can hear a sound, then there must be anything wrong with the keybed or the connectiom to.
But note again: NEVER TOUCH TWO “NEIGHBOURED” PINS AT THE SAME TIME !!!
What you also can do is to remove the upper IC: U28 and put it back in the socket CAREFULLY !!! to brush away oxidations.