Yamaha CS01 Dead Slider?

[bongoben]

Recently picked up this great little Yamaha CS01 synth. Everything works great except the pitch adjustment slider. It is currently tuned a half step low and moving the slider doesn't change the pitch at all. Is the slider dead? Solder joints all look good. I've never replaced one of these before so any help would be greatly appreciated.

20141105_211033(2).jpg (370.86 KiB) Viewed 5555 times

[bongoben]

Alright, so here are my observations/thoughts on this because I'd love to get some feedback from people more knowledgeable than me. First off, my background... I can solder. I worked on arcade pcb's for a few years when I was more into that hobby. I'm not perfect at it but I can hold my own and have re-capped many a monitor pcb to revive those. I can read/make sense of basic schematics. And finally, I love this little synth and really don't want to kill it in trying to fix it.

So the problem I've run into is that sourcing this particular size of slide pot is going to be a pain in the ass. I've talked to a few local electrical fixer types and all have said this is probably a proprietary slider so finding another that would fit would be a pain in the ass. That said, I have ready elsewhere online that this has 25mm of travel so finding another close to that should fit on the pcb just fine. I have three thoughts as to how I could go about fixing this.
1) Find a new slider online with about the same distance of travel and hope I can make it fit. This seems like the most ideal option but could also be the biggest pain in the ass ordering slide pots online, paying more for shipping than the part costs, and praying it works so I don't have to order a different one.
2) Run the lines from this slider over to one of the Breath Control pots as these are not being used since I don't have the Breath Control attachment. The pot values are the same and I've read other mod write-ups about people doing this for other changes.
3) Pull the slider from the EG Depth spot (also a B10k) to use on the Pitch spot. The EG Depth doesn't really do what Yamaha intended for it so it basically turns into a second volume control. That said, it is always fully on. So if I pull this slider to move to the Pitch spot and throw in a 10k resistor in the EG Depth spot this should ideally work.

One problem I'm running into is that the sliders have 5 unlabeled pcb solder points. 2 of them, I believe are ground spots as they seem to be linked to pretty much every other pot throughout the pcb. This would be the "3" point for the slider. The "1" and "2" points I haven't figured out yet. And the final solder point seems to be a stand-alone pcb connection point which isn't connected to any other components on the pcb. With the labeling I'm seeing elsewhere on this pcb it is possible that there are labels underneath the slide pots but until I pull one of them I won't know for sure. This is probably a relatively easy soldering job for anyone with more experience than myself. I should find someone local, find out how much their time is worth as I assume it's only about an hour of real work, and let them deal with it. In the end I'm probably overthinking this and should just dive in with my soldering iron to see what I can do. But if nothing else, typing this out has eaten up a half an hour of my work day so I've got that going for me. Back to work.

[Chankgeez]

Chances are not good that Yamaha will have the slider you need, but it's worth asking.

At the least, they may be able to point you in the right direction.

[bongoben]

Chances are not good that Yamaha will have the slider you need, but it's worth asking.

At the least, they may be able to point you in the right direction.

I didn't even think to ask them. Huh...

[Chankgeez]

Can't hurt, right?

[bongoben]

I may have just saved myself a ton of pain with this thing via recommendations from the vintage synth forums. Had I done more than skim through the service manual to get to the schematics I would have seen this.
TLDR version:
-CS01 sliders are rubbish and not worth replacing
-I missed that VR3 on the pcb adjusts voltage to pitch
-Will try this weekend
-
-Profit?

[Chankgeez]

There you go.

[frodog]

Damn, ok I'm bumping this cuz I have the same conundrum now... About to maybe buy a Yamaha CS01 II for cheap where the LFO slider is dead.

Anyone?

[Chankgeez]

You could look on the vintage synth forum or you could PM bongoben and ask how it worked out for him?

[frodog]

Thanks, will do. Think I'm buying it either way though.

[Chankgeez]

[bongoben]

Hey. I ended up just leaving the slider. I found a pot inside that adjusts the overall tuning so got the synth tuned correctly and just left it. Not having the ability to adjust tuning with that slider was never an issue for me.

[frodog]

Yo, thanks for the info! I'll try to find another solution for adjusting the LFO if necessary. Although, in the past I was able to buy a replacement volume slider for my SHS10 keytar from Yamaha in Norway, so I'll contact them too and hear if they have the part.