Escher Sketch not syncing

there’s another thread here:

and another here:

and i already took a look thru both with no resolution (in fact i didn’t even realize Escher had a sync input until i noticed the sync jacks while rearranging my rig earlier today as i’ve previously only used it with audio modules). i am beginning to think the sync circuit on mine is faulty but wanted to comb the brains of the community before contacting LZX as i know they have their hands overfull right now trying to get TBC2 and Chromagnon finished up. thanks for the input so far - hopefully someone else will chime in and tell me i’m making a dumb and obvious mistake but if not i’ll just wait for the chaos to die down and send it in for repairs.