13 November 2015

Godin Multiac SA Nylon



This is one repair that's isn't really a repair.The owner claim the electronics ceased/went silent after a while.Firstly I never had any experience with RMC electronics before,secondly I don't think they sell parts directly.Maybe you can do so through a Godin dealer.?Thirdly..the guitar worked fine in my possession.

But I did found the string output being inconsistent.The Low E loud,the A's soft,the D's loud,the G's soft,the B's loud and the high E is soft.Before I get my scope on the bench,a schematic search commence while doing a pcb visual check.There were no schematic found online so I proceed with the latter.


The piezos are discrete unlike the conventional one piece unit use by many makers.The most I saw before this was two piece piezo's from Takamine and another brand I couldn't remember..maybe Lakewood I think.


Each of the piezo element are soldered individually on the pcb.From the looks of it someone had a go at it.It looks intact but to be sure I unsolder it and re solder it,also a bit surrounding the op amp just in case.I doubt the alternate loud soft symptom be caused by the op amp.














Because the piezo's are individually made,I suspect it didn't sit proper and vertical enough.Its just my hunch and since I never had any experience with any/all RMC products,its quiet intimidating but I decided to give it a shot.Is it just the piezo or is there anything more under there.The piezos came out fairly easy but there were also some sort of brass shim.Is there anything under that bras shim?sure enough while taking the shim out very very carefully,it broke at the end.Well you'll learn new things on first attempt and that's part of learning the trade.I tell all my client that all the time.That's how I fix thing.If its a new thing for me,I need them to trust my call or methods.So far,so good.Most of my client are quiet supportive about my practical endeavour weak know how in some areas plus my shit work gets posted on line as guide to others.





Coming back to my shit work.I put the shim back in(with the broken piece) and it work without a flaw.All output from the strings are loud and crystal clear.What did do? Was it because of the broken shim that it work great? I don't think so.I think the piezos needed resitting for adequate string pressure on it.










I found the nice battery connector to be loose so I direct wired a wired type.The default battery connector serves as battery holder and its pretty secured.The control plate was missing so I was assign to make one with clear acrylic.That's that then.Oh yes..one more...If you like looking at pcb's or curious about RMC's pcb's,enjoy the below pictures.





















Hunch and touch cost money
yustech




 

2 comments:

pmoirinho said...

Hi
I have a godin to put it to work, with electronics like this
but it happens that it lacks the jack and MIDI input board
so also without schema
I can get it to work passively with jack socket
but I can't put it with the equalization and volume
the midi part is not relevant, I don't need it
is there an idea to get it to work normally if taking MIDI?
THANK YOU for your attention

Antonio Astorino said...

Hello, just a question , do you have a picture where I could see the transistor reference (504 2N ... something 04), mine is not readable completely on the first board (not the one with the controls). Brgds