Panelsettings and sound om my Minimoog Voyager change spontaneously

[dth]

The display panel on my Voyager cycles like crazy through all of the knob settings. Sometimes it is gone for a few days, a few weeks or even some months, but unfortunately it always reappears. At first I thought it was some kind of midi-loop but even after disconnecting all the other gear (laptop, mixer, moogerfoogers etc.) and using only a headphone, the panel settings, sound and sometimes also the memory presets, change spontaneously.

On Moog's recommendation, I installed a new digital board but problems are still the same. I therefore reinstalled the original digital board.

What can possibly be wrong?

[till]

The power to the knobs is not stable and clean. And therefor the pot scanning gives random values around the set value.

[dth]

Thanks for your quick and clear response. Could this instability regarding the power to the knobs perhaps be caused by a (faulty) power supply or possibly something else (loose contacts etc.)?

[till]

These could be the cause. There might be others. But I am not a technician.

[Acid Mitch]

I had this exact same problem. I sent the Voyager to Source distribution who are official Moog UK service centre.
It took many months to diagnose and fix. Mainly because the fault was intermittent and could take days or weeks to show up. Firstly they replaced the power regulator and reflowed the solder joints. They sent it back and I still had the same problem so they ended up just replacing the whole power supply because they couldn't find the exact cause. It has been fine ever since.

I will include some quotes from the tech department to give you some idea of what happened.
This was what I was told at first.

I’ve narrowed it down to either the analog-to-digital conversion between the pots and the digital ‘brain’, or the other side of the brain in the digital-to-analog conversion before the analog synthesis circuitry

It looks like the ADC/DAC behaviour was only a symptom of the power regulator circuit intermittently failing. I also found a couple cold solder joints connecting between the mains power and the regulating board, which could be a reason as to why the regulator board began failing.

Then I got the Voyager back, had same issue 5 minutes after plugging in and had to return it again. Source covered the return shipping.

This time round I’ve found that the cause of the fault is what I discovered last time – there’s definitely some inconsistent connection/cold solder somewhere in the PSU assembly – but I’ve tried reflowing everything on your board, replacing connectors and wires but it still wasn’t 100% fine. I replaced the PSU with a new one we have here and for the last week the Voyager has been completely stable

So to be clear - it took a new power supply to fix the problem. Trying to repair the old one didn't work. Got it back about a year ago and I have had no problems since.

Many thanks to Connor and the team at Source Distribution.

[dth]

Thanks for your comprehensive and clear response, your description of the problems you had with your Voyager look exactly similar to mine. I guess there is nothing else for me to do but get the powersupply replaced as well. But given the experiences described in your reply, this might be the right solution. Thanks again for your reply!