Voyager XL VCF (and other) hardware issues

[Afturmath]

Last year, I bought an early-SN Voyager XL secondhand from a well-known celebrity musician, but unfortunately it has a couple problems. I was wondering if anyone may be able to help point me to some advanced technical resources. I tried reaching out to Moog support 2 weeks ago and even tried bumping my ticket, but I got no response.

1: The 4th pole of the VCF does not work. Initially it worked around 25% of the time in one channel (left), but now there's no audio from either channel. 1-3 pole modes work fine in both dual LPF and HPF/LPF in both channels.
2: The on/off switch for Osc 2 in the mixer doesn't work.
3: MIDI-thru doesn't work. There appears to be no electrical signal coming from the Thru port.

I read on the sites mentioned above that units under serial number 500 may have issues with the early revision of the analog board, and I was wondering if that may be causing issue 1 and/or 2. I also read there was an update to the digital board, and I'm wondering if that might be the cause of issue 3. I've examined all the screw heads on the panel of my XL, and they appear to be factory-fresh with no obvious signs the unit has ever been opened.

With all of that being said, I am pretty handy with electronics repair and testing, and I was wondering if anyone knew if it would be possible to repair any of this myself. Does anyone have a service schematic for the analog board?

[ummagumma]

well first of all congrats on the XL, I think they are fantastic synths; I have been using mine & getting more familiar with it again, after being distracted by a D and a Grandmother

I think all those clues indicate your unit may have board issues & need Moog to look at it, surprised they have not responded

what version OS does it have now? you could try updating the OS & see if that kicks anything back in

afaik no public service schematics etc are available. But I have read here that Moog were very helpful with others, who had early board issues

good luck!

[ummagumma]

ps has it ever been shipped?

maybe try reseating the cable connectors on the boards; I have read about loose connectors inside causing funky issues

[Afturmath]

well first of all congrats on the XL, I think they are fantastic synths; I have been using mine & getting more familiar with it again, after being distracted by a D and a Grandmother

I think all those clues indicate your unit may have board issues & need Moog to look at it, surprised they have not responded

Thank you! It's the third (hardware) Moog in my studio after the Mother 32 and Moogfest-edition Subsequent 37 CV. I've been impressed by everything so far!
I suspected it was a combination of board issues, and I'm less than thrilled about the lack of response from support. I'm going to ask around in person at Moogfest next week and see if I can get direct support or kickstart the ticket process. I had much better response times for my Subsequent 37 CV and Mother 32 support requests.

what version OS does it have now? you could try updating the OS & see if that kicks anything back in

It was running the latest 3.6 when I received it, but I re-flashed and re-verified just in case that was the issue. No luck.

ps has it ever been shipped?

maybe try reseating the cable connectors on the boards; I have read about loose connectors inside causing funky issues

It was shipped from Chicago to NYC and probably multiple times before that. I'm going to crack it open after Moogfest and check.

Thank you for your responses. I'll keep trying with Moog support.