Joined: 27 Aug 2008
|Posted: Wed Aug 27, 2008 10:02 pm Post subject: Memorymoog pot problem
|I've been bringing a Memorymoog with lots of faults back from the dead but I'm left with one last fault.
It's one of those niggling annoying problems that seems to be undetectable...its driving me nuts..I'll try to explain it better.
Basically you turn a pot on this synth and the pots value is shown on the alpha/dec LED display, you turn the second pot the display instantly shows that pots value..so far so good...but after a few turns of various pots, it will stick on a value and won't change with the new pot movements, pressing buttons, turning other pots wont get rid of it(you can see the correct values flickering behind it)..even turning it on and off. You have to go back and find the pot thats got the value 'stuck'. Zero that pot and it's fine again. It's totally random and depends on the combination of pots and values. The actual sound itself changes fine with the pot movement. It's just the displaying of the values that is a bit screwed. Its like the displayed values are ocassionaly not being cleared from memory somehow.
Remember is the physical displaying of the values that gets stuck, not the actual values that control the analogue parameters. They are working fine.
I wont tell you what Ive already done in case it influences your diagnosis..lets just say I have tried a lot of things!
If anyone can help I'd really appreciate it, the schems are here: http://www.matrixsynth.com/blog/media/Moog/MemorymoogSchematics/
The service manual is here: http://www.retrosynth.com/docs/memorymoog/mm_service.pdf
Apart from this fault..it seems to be almost fixed.