How To Repair Faders On A Vintage Synthesizer

In this video, Mike Sisk demonstrates how he repairs faders on vintage synths and other electronic gear.

Video Summary:

In this video I show how to repair faders (or slide potentiometers) that are used on many vintage analog synthesizers.

The faders I am repairing are from a Roland SH-1 synthesizer, but this same process will work on other types of faders from other manufacturers as well.

To properly do this, the faders must be individually desoldered from the board and opened up to clean the internal contacts. I do not recommend using the standard “contact cleaner” that you find at most hardware stores, but instead recommend using the more expensive Deoxit cleaner from Ciag. I paid about $24 for a 2oz can of this cleaner, which seems high, but when working on an old vintage synth, it totally turned to be worth every penny.

Have you done potentiometer repairs on your own synths? If so, share any tips you have in the comments!

26 thoughts on “How To Repair Faders On A Vintage Synthesizer

  1. Great video, but if you’re going to actually desolder and resolder the sliders, I recommend replacing them with new stock, if possible. This will give you another 20 years, whereas disassembled and fiddled with sliders are unknown lifespan as they were never intended to be rebuilt. Selecting replacement can be tricky though since you generally want audio quality low noise exact size replacements and those are not always available, or not for a reasonable price.

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    1. Thank you. Before doing this I definitely tried to find new replacements but did not have any luck sourcing the correct parts. So that is why went this route. Also all this option cost me was the can of deoxit, some solder wick and TIME, lot and lots of time. haha.

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  2. If anyone ever figures out how to clean the sliders on a JD-800 I would appreciate hearing how they did it. I opened mine up and used the De-Oxit Fader Lube and the sliders are still jumpy. Oh well.

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    1. Hi Josh
      I cleaned up the sliders on my JD800 as the synth suffered from very bad self-editing… I took it to a synth repair tech who only sprayed deoxit into each slider and it really didnt do very much. I decided to do open heart surgery and it was worth the effort.
      To clean each slider, I firstly desoldered them from the main board in batches of 10 (I numbered each slider and their board position so everything went back into the same location). I then opened up each slider and cleaned it one at a time… I opened up the tabs underneath the slider housing and removed the base plus any plastic moulding inside each slider. I cleaned the base, the internal rod, the internal slider housing plus any plastic fittings with isopropyl alcohol and a cotton tip (Q-tip)… this removed LOTS of dirt and carbon. I re-assembled the slider and them gave it a quick short spray with Deoxit5 (fader lube) and worked it in well by sliding the knob back and forth several times. I then re-soldered the batch of 10 sliders and TESTED the batch of 10 sliders by switching on the JD800 and moving each fixed slider to see if it was recognised by the synth. After every slider was cleaned as I described, I fired up the synth and discovered that the self-editing was cured if I pushed every slider to either the top-most position or to the centre (zero) position (if it has a zero notch) … previously, the synth would self-edit no matter where the sliders were. Now I can leave the synth alone for hours and the patch I’ve selected stays the same … it’s a lot of work and you’ll need a clear space to work but it’s not a hard job… just label everything, clean and test in batches (and label each position) and you should be OK…. slow and steady is the secret. Good luck!!

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    1. Funny, I’ve never even knew about a desoldering gun until just now. I’ve always used the wick. Might have to look into that. Thank you.

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  3. If you own and value a vintage synth, take it to an expert. Do not attempt to do as much as open the case. I speak from experience.

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    1. Sorry but I sort of disagree with you there. Doing these repairs are really not that difficult as long as you are comfortable with a soldering iron. However if you are total novice than I could see how you might struggle a bit. These old circuit boards are so much easier to work on compared to something new with SMD like a Moog Werkstatt or any of the Korg Volcas.

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      1. He has a point. See my comments further down the page. You might be doing more harm in the long run than good. The might not be any carbon left on the fader pads ny the time you finish cleaning and lubing it your way.

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    2. Vintage synths are very much like vintage cars. They’re wonderful to have, but unless you have a lot of money you’d better be prepared to open the good and get a little dirty.

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    3. If you have some basic electronic skills it pays to DIY.
      Pots and JUNO 106 filters (i.e. desolder and soak to get off resin) are pretty basic fixes.
      Everyone has their limits … I often stay away from the digital stuff … but op-amps, transistor and cap replacements are common (and often easy to diagnose).

      At the end of the day, if you don’ t try you won’t learn.

      With that said, the opposite is also true -> taking the synth to a tech leaves more time for producing music!

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  4. Big praise to people like this who salvage and preserve these increasingly harder to find vintage synths.

    It’s a tough call sometimes deciding to do it yourself or to take it to the repairers.

    Repair shops often do a shoddy job because they have piles of repairs to work through.
    That combined with not trying to overcharge so you come back next time.

    Having a crack at it yourself can be rewarding in many ways, depending on the job, but with a wealth of information out there such as this video, all else you need really is to be patient, methodical and fearless.

    You learn heaps along the way too, so you get a better understanding of how stuff works.

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  5. I prefer to always replace a signal fader (audio flow through it) even if I have to make some extra work to mount it on the pcb as most of the older faders have different pinout that those in the market today.
    Fader frequency response is altered with usage and time as the graphite is used.
    A signal generator/oscilloscope can be user to test a fader for that.

    For a control fader (audio not flow through it) the repair process most of the time will do he job (if the fader is in a good condition)

    A microscope can help to check the graphite condition.

    An analog multimeter is essential to test the fader resistance and how is altered as the fader moves and discover any continuity problems. A digital multimeter can only display the resistance on specific fader positions.

    A desolder station/gun (electrical sucker) is essential to work with vintage equipment.
    Usually a lot of switches and other components need to be replaced as well.
    The desolder gun saves time and preserves pcb and components from damage.

    Desolder pumps are nice to work with cables/jacks but I am not use it on pcb and components.

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    1. Thanks for the tips! Sounds like you are much more of an expert in this area than I am. I definitely would like to someday get a scope but those are just not in my price range at the moment. I’ll look into getting a desolder gun and analog multimeter though. Thanks again.

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    2. You absolutely need a desolder pump for double-sided/multilayer/plated thru hole boards. For some reason most vintage synths use plain ol’ single-sided boards for the panel controls, so desoldering wick works well enough.

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    1. Yes you are correct but I could not find any Deoxit Fader lube at the time. I have some on order and will give each fader a quick shot through the top slot once it arrives.

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      1. Don’t do that. The lube will get down on the carbon tracks. It needs to be only on the sides of the white plastic fader part. Use it sparingly. You will need to open them all up again if you plan to lube them.

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  6. You shouldn’t use deoxit on the carbon resistor pads on the bottom inside of the faders. It can remove the carbon and will no longer conduct. Just use a qtip to gently wipe it clean. The rest can be cleaned with alcohol. You should use a bit of lube on the sides of the white plastic fader part before reassembling. A light white grease will work if you do not have the deoxit brand one. I have used fishing reel grease since I always have some of that in my shop.

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    1. Thanks for watching and commenting but do you have any sources to back that claim up? I used Deoxit D100 which is solvent less and according to the Caig website is the correct one to use on carbon resistor pads that are 40 years old. Caig does mention not to use Deoxit D5 as that type has a solvent and it may wash away some of the carbon like you said. Also there was NO WAY a dry q-tip would have worked as you suggested. Caig also does not recommend using alcohol either. Below is a link to the caig website where I found that info. Before doing this my faders barely even worked and some were super hard to move. Now they ALL work and ALL slide fairly well. I do agree that I probably should have lubed before reassembling but Caig also points out in the link below that D100 “has the addition benefit of providing lubrication” so I think I’m all good. Thanks again for your opinion but I have to respectfully disagree.

      http://store.caig.com/s.nl/ctype.KB/it.I/id.1809/KB.215/.f

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  7. hey that was very useful, thanks for posting this & all the comments too

    –>not sliders, but what do you recommend as a lube, to get that silky smooth feeling back to Moog rotary knobs, after they have been flushed with deoxit? they lose all their resistance and spin too easily after cleaning. thanks!

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