Hello,
This is a Roland MC-505 synthesizer I bought used years ago and 1 of the knobs was bent.
Eventually it started 'ghost editing' by changing the parameter of this knob on its own.
I resoldered the 5 pins on this knob (the two larger solder spots above these 3 smaller ones is for the same knob).
Then it started happening again, or maybe the knob stopped working totally (I set it aside months ago and forgot about it).
I bought a replacement knob/Potentiometer but when I recently opened it up, it seems the previous repair I did didn't 'stick' and wasn't making good contact. So I'm trying to use the same Potentiometer.
The previous repair was atrocious. I used a $5.50 harbor freight 30W non-adjustable pen-style iron and it was tricky to get the 3 small prongs soldered, I'm surprised it even worked and didn't short from solder touching eachother.
I got decent at soldering recently repaired headphones and learned I was doing it wrong before by trying to basically transfer globs of solder from the iron to the work instead of heating the work for a couple seconds and touching solder to it. I also didn't use flux or anything before. I'm using a digital ~$14 80W Chinese eBay pen-style iron with various tips and it seems to be ok.
I just did the 2 larger solder spots and then noticed the circle pads on 2 of the 3 smaller pins are detached!, and one seems to have vanished but I think it was working like that. I guess I added too much heat previously or that there was some wobble from using the knob on the synthesizer.
The pic with the screwdriver is spare parts of a stereo I took from the curb to practice on so maybe I can use something from that? The circle pads are really tiny like 2mm diameter.
What do these pads even do? They transfer electricity to the darker green lines/tracks on the board? The solder is supposed to touch the dark green surrounding tracks, or no? I don't get why these pads are even there, are they supposed to insulate/isolate electricity from the board (light green).
any help greatly appreciated. thank you
This is a Roland MC-505 synthesizer I bought used years ago and 1 of the knobs was bent.
Eventually it started 'ghost editing' by changing the parameter of this knob on its own.
I resoldered the 5 pins on this knob (the two larger solder spots above these 3 smaller ones is for the same knob).
Then it started happening again, or maybe the knob stopped working totally (I set it aside months ago and forgot about it).
I bought a replacement knob/Potentiometer but when I recently opened it up, it seems the previous repair I did didn't 'stick' and wasn't making good contact. So I'm trying to use the same Potentiometer.
The previous repair was atrocious. I used a $5.50 harbor freight 30W non-adjustable pen-style iron and it was tricky to get the 3 small prongs soldered, I'm surprised it even worked and didn't short from solder touching eachother.
I got decent at soldering recently repaired headphones and learned I was doing it wrong before by trying to basically transfer globs of solder from the iron to the work instead of heating the work for a couple seconds and touching solder to it. I also didn't use flux or anything before. I'm using a digital ~$14 80W Chinese eBay pen-style iron with various tips and it seems to be ok.
I just did the 2 larger solder spots and then noticed the circle pads on 2 of the 3 smaller pins are detached!, and one seems to have vanished but I think it was working like that. I guess I added too much heat previously or that there was some wobble from using the knob on the synthesizer.
The pic with the screwdriver is spare parts of a stereo I took from the curb to practice on so maybe I can use something from that? The circle pads are really tiny like 2mm diameter.
What do these pads even do? They transfer electricity to the darker green lines/tracks on the board? The solder is supposed to touch the dark green surrounding tracks, or no? I don't get why these pads are even there, are they supposed to insulate/isolate electricity from the board (light green).
any help greatly appreciated. thank you
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