Grandmother sync and mod fault

The Moog Forum Moog Semi-Modular Analog Synthesizers
1

Hi all,

apologies for my first post here being a grumbly one.
I’ve recently got a GM and having some trouble. The sync button doesn’;t do anything. No effect on the sound and doesn’t light up.
I’ve tried updating the firmware but that process didn’t work either. No arp lights showing the codes or anything and I’ve no way of knowing if it worked or not.
Either way the behaviour of the sync button didn’t change.

To cpmpound this, now the mod rate control does nothing. The light flashes with a steady pulse but turning the knob changes nothing. The oscillator is fine though I think, because if I patch the attenuator out into the mod rate I can change it.

Any thoughts on this more than welcome.

Thanks

Rob

2

not sure how useful this is, but if the firmware update didn’t work that is probably the root cause

did you follow this procedure? you need to erase the old firmware first

https://www.sweetwater.com/sweetcare/articles/moog-grandmother-calibrate-and-update/

also make sure you always use the power button on the GM for on/off. I had mine hooked up to a power bar and it started acting funky if I used the powerbar for powerup/down. makes sense as it has a CPU