Vintage Synth Explorer Forums

Ok guys. I'm really unsure of how to get started here, so please cut me a break. I wish I was on a laptop and not my phone, seems like it would be easier. Please help!

I've got the above mentioned board. It works, kind of. The majority of the tones you can choose have no response, but piano and guitar (I think work). A few others come in spotty/crackle occasionally.

Now, combine that with the volume control issue. As you turn up/down the volume it will crackle and fade in and out. The volume at Max doesn't work at all. But as you turn it down, it will crack and the sound will come back in.

I've got some experience soldering and working with small electronics, and I think I can fix this but I don't know where to begin. I've already got the thing open and am poking around.

I bought this off someone and it was like this upon purchase. Any advice or suggestions would be greatly appreciated.

I apologise if I did not post this correctly, I'm a little lost.

Thanks!

Edit: 4 years later: Cleaned with contact cleaner (WD40 brand) on all the spring-loaded buttons and the pots. Cleared it up. Don't remember even POSTING this the first time, but I guess having a child will do that to you. The portasound is working, now. One key is faulty, but I'm looking into that.

If the volume is controlled by a potentiometer, then try cleaning it. The behavior you describe is consistent with pots that have a lot of crud built up inside over the years.

It's likely the switches for the other sounds also need cleaning or replacement.

Thanks, I'll try that. Any pointers on cleaning? I figured I'd use 70% IPA as my agent. Also, do I need to disassemble all the buttons (springs etc) to clean or is there a trick of the trade?

I really appreciate your response, some things you just cant find through Google.

Ok, thought I posted a reply, but didn't seem to take. Thanks for the advice. Is the potentiometer just another word for the inner workings of the knob that runs sound control? I'm going to take it apart and use 70 percent IPA to clean the parts. Any advice going forward?

Update: I cleaned the potentiometer for volume (and all). I now have full volume control, a couple of the sound pads that weren't working now are, but they seem to be going in and out of service.

The update is, sound is travelling through ALL of the selectable tones. I can barely hear each one of them with the volume all the way up. The final 3 or 4 are working at maximum capacity. This leads me to believe that I don't need to replace the buttons, could dirt within the actual switch be causing this or is it somewhere between the button and the speaker.

This is outside of my wheelhouse, but I'm a reasonably smart guy. I've got the schematic butttttt I can only surface understand it.