MT-400v - Having some problems. Any ideas?

[534N]

Hi, I'm new. I hope I am posting this is the right place.

 

I just bought a Casio MT-400v for about $20 and it's in pretty awesome cosmetic shape considering its age. I got the speakers and none of the slider pieces are missing.

 

Unfortunately, there are some functional issues.
 

1. the filter section and "waw" functions don't work at all

2. the output has a noisy background hum/buzz to it

3. the selector buttons for rhythm and tone don't stay press down for the secondary options (they work if they are held down)

4. there are lots of inconsistent changes when I use the sliders.. the changes are not smooth.. they jump around

 

I assume this is because there is some funk built up in the sliders and they are not making good electrical contact. I sprayed some Deoxit D5 down into the sliders that had obvious passage into the mechanism from the outside, but many of the other sliders (with the present clicks) don't appear to be Deoxit-able from the outside. I hope this makes sense. I'm new to this.

 

Anyway, this is my dream keyboard and it took forever for one to show up for sale. I'm determined to fix it but I could use some tips if anyone is feeling nice. Also, I am looking for the service manual (not the owner's manual.. I already found that) and I can't find it ANYWHERE on the internet. It appears there was a post in the past about this and maybe someone shared the document I need, but it's no longer hosted on the server so I can't download it. I know the MT-65 and MT-68 basically have the same internal stuff, but since I don't have a lot of experience with this stuff yet, I'd like to find the MT-400v service manual/schematic specifically to avoid confusion.

 

I imagine I will need to disassemble the keyboard and clean the slider pots one by one by taking them apart. I'd prefer not to do this but maybe it's the only way. Please let me know if you have any advice before I go into this without knowing what I'm doing. I've watched some Youtube videos and I think I understand the main ideas, but I don't want to make any rookie mistakes that totally brick the keyboard.

 

I think cleaning the sliders will fix a lot of the problems, but I don't know about the background noise and the filter section. Those are the main things I want to address since the keyboard loses its main mojo without the filter section and is basically useless for recording with the extra noise.

 

Thank you so much if you are still reading. I am really hoping someone can help me resurrect this thing. :)

[pianokeyjoe]

By chance the battery compartment stained or messy with old battery acid residue? AND, did you use a 9VDC Center pin NEGATIVE 500mA or higher amps AC to DC power adapter? Cleaning the sliders AND cleaning the push button SELECT button underneath where there is a little spring(it is either gunked up-most likely- or missing), that should help alot. The filter sliders are soldered on like the volume pots so cleaning should be done with a lubricating electronic contact cleaner and not a cleaner that dries the slider carbon or you will ruin the synth further. I suspect battery acid issues here but also dog or cat hair type gunk in the sliders.. MOST used Casios have one or both of these scenarios in my experience.

Edited October 20, 2022 by pianokeyjoe
adding more info.

[534N]

Thank you for the reply!

Fortunately, there's no visible battery acid damage. I carefully searched for that first. Also, I am using the correct adapter and always have (9v, negative center, 1000mA, DC) but I can't be sure about its past usage. Who knows how many hands this keyboard has been through until now since it's been around since 1983 or so. It had some cobwebs and a dead spider inside as well as a good amount of dust so I get the idea that it sat in the corner of someone's garage or attic for ages before it saw the light of day again. The keys are a bit yellowed and have sticker residue from someone labeling the key names. It definitely looks its age, but still in pretty great cosmetic condition overall, all things considered.

 

Do you know if Deoxit D5 is lubricated enough to keep the carbon strips from getting too dry? I hope so because it was really expensive to get it here in Thailand. I'm looking at the Fader version because it has added lubrication, but it's even more expensive than the D5. I don't want to add to the damage, but I'm really not looking forward to opening this thing up and taking the sliders apart one by one and having to desolder and re-solder. Do you know if it's ok to just spray the Deoxit down into all of the buttons and sliders or will cleaning definitely require disassembling the whole thing? I know the second option is the more guaranteed route, but just checking if the first option could work.

 

I watched a Youtube video from Keen on Keys which showed a little bit of a sped up montage of taking it apart and vaguely explaining the process, but I'm hesitant to do this without having done it before because I don't want to make matters worse. I was thinking there may be a bad component or weakened connection somewhere in the circuit but I don't feel super confident yet about testing everything piece by piece since I'm still fairly new to this and don't have a good workspace to keep everything in order.

 

Thanks again for any info you may have on this process. I'm hoping it's not a lost cause to bring the filter section back to life. I notice when I switch the selector switch to the tone and white noise functions, it does things, but the filter sliders have no effect at all when I move them. I'm sad the "waw" function doesn't work at all either. That's one of the coolest parts.

[pianokeyjoe]

Sadly you need to take the unit apart but you do NOT have to desolder the sliders. Once the board with the sliders is exposed, you can clean the sliders with cotton swabs and alcohol or contact cleaner one by one. Getting all the fuzz and dust out of each slider FIRST. When that is done, slide the sliders back and forth a few times fast. As for the BUTTONS, those are plastic tops with rubber silicone dome contacts so a simple wiping of the circuit board with paper towel socked in rubbing alcohol should be enough. You mainly have to get rid of all the dust, fuzz,built up gummed up residue and just wipe that sucker all down inside and out. THEN you can really KNOW what is wrong. Now as for the filter/waw section not working, that is down to the switch that turns that section on. It is a slider too but NOT the same as the filter and volume sliders which as self contained solder on pots. The sliders for switching the functions on and off are wipers on carbon contacts on the circuit board(control panel). Same as with the push buttons, wipe the circuit board with paper towel soaked in alcohol. Wipe the bottom of the slider wiper, being careful NOT to lose the tiny metal ball and spring on the side! You have to essentially REBUILD or REMANUFACTURE the keyboard. There is no getting around that. I did it with my MT65 I got from my uncle. It was a true artifact from my childhood and sadly it too had to be completely disassembled and cleaned, the keys re lubed with lithium grease, etc. You will need to resolder some joints on the ribbon cables if they break so be aware of that. Keen on Keys does what I have been doing for years. I think he is actually 10 or 13 years younger than me so.. I hope you can restore your Casio Gem!

[534N]

I really appreciate your thorough tips and honesty. I will definitely follow your advice and wait until I can fully open the keyboard up. It gave me some hope to know that there's a possible fix. I just received a big carton of isopropyl alcohol today so I'll be ready to go to town on this thing when I have the time. I think it truly is a gem from the 80s. I love everything about the form factor and functions. There's nothing unnecessary, unlike many others that came after it.

 

I also have an MT-68 which is in good condition. As I'm sure you know, this is the twin brother of the MT-65. I love that thing. It would be the ultimate keyboard of this type if it had the filter section, waw and stereo chorus. I wish it was 9v also because it would be easier to use with my guitar pedal setup, which I like to connect. These are the few reasons I am eager to get this 400v back to 100%. I just hope I'm capable of doing it. Anyway, thank you again!

 

By any chance, would you happen to have the schematic document for the 400v or know where I could find it? I can't find it, even in the darkest corners of the internet. Sigh..

[534N]

This thread will likely fade out from here because there may be nothing more for anyone to add on the topic of repair/cleanup, but I wanted to share my experience tonight. I plugged in my MT-68 and played around for a couple hours and I realized that (my opinion for the moment) it ultimately has way more creative potential than the 400v because of its arpeggiator and the simplified modulation options. The filter section of the 400v is super cool and I love the way it feels and looks, but it's really awesome that the MT-68 (and 65 variation) creates shortcuts to even more amazing features at a quick tap. I wish I had grown up with one of these in my hands.

Actually, I grew up with a Casio MT-140 always at the ready in the hallway next to my room. The cheesy 80s pop style demo song is forever ingrained into my memory because of this. A couple days ago, I saw a perfect one pop up for sale and I thought about buying it, but I don't feel like it would do much for me now after watching a Youtube review. It's special, but it doesn't have the warmth and creative variability of some other models like the ones we're talking about here. .. But oh, the nostalgia..

 

I can't decide how far I want to dive into this community of Casio keyboard lovers, but there's some special magic in these old models that none of the later models capture. I'm very intrigued.

 

For anyone who happens upon this thread, feel free to share an experience or suggestion of (a) keyboard(s) that have totally entranced you in a nostalgic way. At the moment, I have collected a Yamaha MK-100, Casio MT-68, MT-400v and I'm thinking about grabbing up the MT-140 again to be my DeLorean. Great Scott, what have I gotten myself into?

[pianokeyjoe]

Well sir, I hope you can fix the MT400V. I grew up playing the MT65 and indeed have that very unit from my Uncle as a gift to me as I may have mentioned. The MT11 was the first polyphonic Casio I ever enjoyed though at the time it was a loaner. The first Casio I owned was the PT1 in cream yellow with lilac sharps and flats. I own one or several of these models as back ups. I also borrowed and recorded music with the MT45 and then owned my very own MT46(gold color variation). I am officially a CASIO LOVER(CASIONOVA) if ever there was one! I bought the MT240 with my first ever paycheck at 14 years.. I KNOW all about the nostalgia lol!, I have several of those as well and have circuit bent them for added hidden synth tones.

[Chas]

@534N- I certainly wouldn't give up on your MT400V, and if you can get it sorted and you wish to have the extra features found on the MT65 and MT68, well, hidden inside the MT400V (and its full size but otherwise identical twin the CT410V) are those very same features. For some reason Casio not to include then in the MT400 and CT410 🤦‍♂️ 

 

By tapping into the LSI matrix and adding extra switches, you can now activate those Easter eggs. Then you will have the equivalent of an MT65/ 68 with added filter, WAW and stereo chorus!

 

You can find details of these Easter eggs on the very informative Table Hooters site:

 

http://weltenschule.de/TableHooters/Casio_CT-410V.html

[534N]

@pianokeyjoe- Thank you for sharing your experiences. Those models look very interesting. I just looked up a Youtube video for the MT-240 and surprise surprise- it has the same exact demo song that was featured on my mom's MT-140 that I grew up with. That is so crazy nostalgic for me. I can hum the whole song perfectly. It's kind of cheesy but I love it.

 

I think my favorite Casio models are the ones that have the same drums as the MT-65/68/400v/etc. I might seek out an MT-52 next because the "super drums" look interesting. It seems to be really rare though. I should probably calm down and clean up this 400v before I get too deep into anything else.

 

@Chas- I appreciate your advice. I also happened upon this site while searching for MT-400v info. I think it was mentioned in a comment on Reddit. It would be funny if that was also you haha. Anyway, it's really awesome to know that these mods are possible. I'm kind of afraid to try them myself since I have very little experience with modification. Recently, I modded a guitar pedal to unlock a feature and it involved soldering to a tiny micro component. I nearly lost my mind from how frustrating it was. It took so many attempts and I was stressed about bricking the pedal if I failed. I'll try to study this really thoroughly for awhile before I do anything that serious, but I really would love to have a fully unlocked super synth like you described. I would also really love to separate the different accompaniment parts to individual output jacks one day. It would be amazing to have the arpeggiator, bass, drums and the main voice run through different effect pedals or at least isolate them in my recording software for better mixing possibilities. Have you attempted any of these kinds of things yourself? Just curious. Thanks again

[Chas]

On 10/26/2022 at 10:15 AM, 534N said:

@pianokeyjoe- Thank you for sharing your experiences. Those models look very interesting. I just looked up a Youtube video for the MT-240 and surprise surprise- it has the same exact demo song that was featured on my mom's MT-140 that I grew up with. That is so crazy nostalgic for me. I can hum the whole song perfectly. It's kind of cheesy but I love it.

 

I think my favorite Casio models are the ones that have the same drums as the MT-65/68/400v/etc. I might seek out an MT-52 next because the "super drums" look interesting. It seems to be really rare though. I should probably calm down and clean up this 400v before I get too deep into anything else.

 

@Chas- I appreciate your advice. I also happened upon this site while searching for MT-400v info. I think it was mentioned in a comment on Reddit. It would be funny if that was also you haha. Anyway, it's really awesome to know that these mods are possible. I'm kind of afraid to try them myself since I have very little experience with modification. Recently, I modded a guitar pedal to unlock a feature and it involved soldering to a tiny micro component. I nearly lost my mind from how frustrating it was. It took so many attempts and I was stressed about bricking the pedal if I failed. I'll try to study this really thoroughly for awhile before I do anything that serious, but I really would love to have a fully unlocked super synth like you described. I would also really love to separate the different accompaniment parts to individual output jacks one day. It would be amazing to have the arpeggiator, bass, drums and the main voice run through different effect pedals or at least isolate them in my recording software for better mixing possibilities. Have you attempted any of these kinds of things yourself? Just curious. Thanks again

 

@534N - I don't think that was me on Reddit, as I don't recall posting on that site. Certainly not in the last few years, though many years ago when the internet was a much different place, maybe I did!

 

I totally understand your reservation when it comes to modifying instruments. I'm not a fan of doing this kind of thing, mostly because I only have basic electronics  and soldering skills and wouldn't want to damage anything. I'm also not much of a fan of "circuit bending", where much of the time the "bent" instruments just end up making random and in many cases unusable glitch sounds. As the saying goes, "just because you can, doesn't mean you should"!

 

Saying that, I also appreciate "circuit enhancing" that to me differentiates from "circuit bending".  For instance, adding a line out to a keyboard that didn't come with one is a no brainer IMO. Unlocking hidden features/ Easter eggs  is also a good thing, and expanding on existing features to give them greater range and usefulness is all good stuff. An example of this is taking the filter in the HT Casios, increasing the resonance and filter range, adding external controls for the filter and making a fare more musical and powerful feature. Of course that would mean having to drill into the case and add extra potentiometers, but if done well, it can almost be made to look factory standard.  And some of the vintage Casios had a ton of extra features that weren't activated in some models, such as the 1980 M10. Check out Robin Whittle's modification guide for the M10 to see just how much more that keyboard can do beyond its original design!

https://www.firstpr.com.au/rwi/casio/

Also, your idea of making individual outs for the accompaniment parts is similar to what I am considering for my MT65 and MT68. I've written a track with mine, but would like to isolate the bass and the arpeggiator, and chord section, so that I can multitrack them and have far better control at mixing them. I've looked at the service manual and it is indeed possible to isolate these parts as they are all routed and summed to a front panel mixer/ volume control. It should possible to tap into and isolate each part's circuit before it reaches the "mixer" and send them to individual line outs. Another alternative that I am more likely to consider is to break the circuit traces for these parts, bridge them with switches, and then you can turn on or off any combination of parts at will. What holds me back though is the need to add switches somewhere, and I don't really want to spoil the clean aesthetics of these vintage keyboards. My other thought is to use microswitches on an extendable loom that can be hidden in the battery compartment. When needed, take off the battery compartment cover and pull out the switches, and activate/ deactivate each of the parts as required. When finished, set the switches to "default settings" and hide them back in the battery compartment. 

 

One of my many potential projects sitting on a list as long as your arm! 

[534N]

@Chas- I definitely agree with your views on circuit bending versus circuit enhancing. I'm not interested in bringing any glitch sounds out of the circuit. I don't want to mess up a good thing. I just want to bring out the best of what is already there and intended as a final sound. My preference, instead of bending, is to use effects pedals. I don't see any use in drilling holes to add a distortion switch when many of these keyboards already have an output jack to run through some other kind of distortion that is likely to sound way better.

 

I also agree that I don't want to mess up the already-perfected aesthetics of these instruments that are becoming increasingly more rare and sought-after. I think your idea of the hidden battery compartment extension is great. I'm not into the idea of using batteries so that compartment would serve a much better purpose as secret switchboard holder.

 

I'm fascinated by this image of breaking the circuit path to bridge with a switch. This set of words (which should be really obvious) was really insightful for me in a visual way. I appreciate your simplification of the circuit and how it has kind of a "mixer" that puts all the signals together at the end of the process.

 

I imagine I will have to do a lot more research and planning before I get to this level of understanding and confidence but I feel like this thread is unlocking the first steps of that journey. Thank you for all of your valuable feedback!

 

I am hoping I don't end up with a list of plans as long as my arm. I already have too many ideas in my head with music in general. This is only supposed to be a side quest. Ahh.. I hope I don't get sucked down the mini keyboard rabbit hole (though I'm kind of poking at it to make it happen too).

[Chas]

@534N - I've uploaded the MT65/ 68 & CT405 Service Manual and Parts List to the files section. You can download it via this link:

 

 

 

Go to Page 16 of the actual manual (your PDF reader will probably show Page 21), and you'll see a block diagram showing the routing of all the main parts. Coming out of the main LSI you can see the Bass, Arpeggio and Chord Circuits next to each other, these go through individual filters, then they are summed into Mixer 1 before passing through a volume control potentiometer. This potentiometer is the actual  accompaniment volume control on the MT65's front panel. Therefore it should be possible to insert switches between each of these three circuits and the mixer  to individually turn them on and off before they get to the mixer.

 

Note that percussion circuit is covered on Page 17 and 22. On P.17 it shows that the main LSI sends triggers to the percussion circuit, and that's because unlike the melody and accompaniment sections, the percussion is generated by separate analogue circuit boards. If you take one of these Casios apart, you'll find the  separate percussion circuit board (they're normally brown coloured) full of discrete components and trim pots. Some even have the drum parts printed on the board i.e. SD, BD, HH etc. It should be possible to locate the line out for each percussion instrument and then send them to an individual output.  P.22 shows the circuit for each drum/ percussion part with a brief explanation as to how the sound is generated.     

 

Hope this helps, and welcome to the mini keyboard rabbit hole!

[534N]

@Chas- Wow, thank you for the document and your thorough notes. I will need some time to digest this haha.. I am still learning the terminology and format for this stuff.

 

I notice that the 400v model is not specifically mentioned in this service manual. Do you know if all the things correspond directly or if this is this only useful for the MT-65 and 68 models? Sorry for all the newbie questions here. Hopefully others will see this one day and relate to my lack of understanding. This will help them skip all the (possibly silly) questions I'm asking here. I haven't been able to find answers anywhere else and it seems there isn't a specific MT-400v service manual file available anywhere on the internet.

 

I'm thinking because my 400v is a bit more worn out, I may want try the experiments on that one first after I get it cleaned up and work out the issues with the non-functional sliders and noisy output. It already has lots of scratches so if I mess up, at least I won't ruin something that already looks and sounds great. Maybe I will happen upon another MT-65/68 and change my mind though.

 

I can't be sure when I will start this project, but when I do, I will try to take pictures of the process for fun. I imagine that will involve more questions along the way so I hope there's some kind of satisfaction that is gained from helping. I really appreciate everything, for what it's worth

[534N]

@ChasHEY! Youtube randomly recommended your channel to me. I saw the "Casio Chaos Theory" name and I thought "Hey, that looks familiar... where have I seen that name before??" then I heard you say your name and it clicked haha! Nice channel! I subscribed! 

[Chas]

@534N -  Yup, the Casio Chaos Theory YouTube channel - that be me! I've been on this  forum for quite a number of years under a different name, then about three years ago I decided to set up my own channel on YouTube and Casio Chaos Theory was born. Thank you for subscribing! 🙂

Regarding the Service Manual for the MT65/ 68 and CT405, no the MT400V  (nor CT410V) aren't specifically mentioned in it. However, much of the feature set of the MT400V is the same/ identical as those other models, so an MT400V (and CT410V) appear to share much of the same circuitry with the exception of  the filter, stereo chorus and "waw" LFO.  I haven't checked myself, but if you open up and check the circuit boards of the MT400V and compare it with the MT65/ 68 and CT405 Service Manual, there's a good chance you'll find much is the same, if not almost identical. This is very common among some series of Casios, as Casio often repackaged and added/ subtracted features to create "new" models. That's also why some Casios are full of "Easter Eggs", as it was common to use the same main LSI CPU across a large range of models, but engage/ disengage features depending on the market sector and price point they were targeting.

When you get the chance, have a look inside your MT400V and compare the circuit boards with those shown in the MT65/ 68 & CT405 Service Manual. There's a good chance you'll find a lot of matching, and that will help you to locate and diagnose issues and/ or add those switches I mentioned.

 

Good luck, keep us updated and hope that you can get your MT400 fixed up. 👍

 

 

[CYBERYOGI =CO=Windler]

The special hardware in MT-400V/CT410-V is only the analogue VCF with sliders.

 

Do NOT attempt to use contact cleaner in those slide potentiometers. It may dissolve the carbon track (has nothing to do with "dry out" or whatever) and permanently destroy them! Contact cleaner is for metal contacts only, so also do not clean carbon contacts on the PCB with it. Before trying anything harsher, first try to only suck dust out by vacuum cleaner (on low setting) and play a round of Decathlon (move 20x quickly to both ends) on the sliders.

 

If it doesn't help, you may insert a cotton swab with isopropanol or (safer) destilled water to clean the track, but do not press hard, else it may ruin it. (Let it dry before use.) If the track is broken/worn anyway, you may try to fix the gap with soft pencil (the graphite conducts electricity).

[534N]

@Chas- Thank you for the extra info. I'm not sure I know enough about circuit diagrams yet to attempt finding all the correlation in the circuits but I will try my best.

 

@CYBERYOGI =CO=Windler - Wow... I wish I had known about not using contact cleaner. It seemed like most people recommended using DeOxit (that's contact cleaner, right?) and had good results. I honestly don't have a clue what I'm doing yet. I just listen to what seemingly more experienced people have said online. I reaaaally hope I haven't ruined the graphite tracks that you described. I have isopropyl alcohol also, but unfortunately, I may have already done damage by using DeOxit D5. The keyboard still functions but it's noisy and the waw/analog filter section doesn't work at all. It seems to change the sound slightly when I move the slider that selects which thing to run through the filter, but it's mostly useless. I haven't had the time or the workspace arranged for safely disassembling everything yet, so it's all a mystery still. The poor keyboard is leaning against the wall in a corner waiting for its day to shine. I think about it pretty much every day when I see it. Sigh.. Anyway, thank you for your input. Noted.

[534N]

@CYBERYOGI =CO=Windler- I was shocked by the information you posted here since I saw so much praise for DeOxit products on potentiometers. I did a quick Google search to see what I could find on the subject and I found this video:

 

 

 

I know it's not a slide potentiometer, but as I understand, it's the same thing basically, but in different form(?) Please correct me if I'm wrong. I will never try to pretend I know anything for sure. This video shows some fairly scientific and logically presented tests that may show evidence to the contrary. I am not leaving this here for argument or anything. Just wanted to share for discussion. I am very open and receptive to all points of view and I'm very interested in everyone's input on matters like this. And of course, I ultimately just want to repair my vintage Casio keyboard in the best possible way.

 

Thank you again for adding to the conversation! I love learning from everyone's comments and being led on new internet researching journeys with the new terms that are mentioned.

[CYBERYOGI =CO=Windler]

The problem is that a potentiometer track is not a solid block of *pure* carbon. It is a paint containing carbon particles in a binder, which depending on its composition (in worst case something like nitro lacquer or spirit lacquer) may dissolve by organic solvents and so flush the carbon powder away. While I have successfully cleaned some pots with Isopropanol (e.g. a Casio MT-70 which is delicate to dismantle for access), e.g. slide pots in 1980th Bontempi keyboards react extremely sensitive on such chemicals. Thus I recommend to clean only with distilled water and a cotton swab (and dry it well) if you can desolder and open it (many slide pot tracks can be accessed without).

 

Already the DeOxit statement "Mineral oil will not damage metals, plastics and carbon" is debunked, because mineral oil (e.g. household "machine oil") does make Bakelite (which by definition is a "plastic") brittle and crumble apart like charcoal, which is e.g. an infamous problem with spilled machine oil on Hammond organ parts. And the statement "If they use one of our sprays with a solvent, if the carbon has been scratched or damaged, the solvent will flush it off the surface." means that it does remove unbonded carbon particles (like a pencil streak), but poorly made old pot tracks are more like a pencil streak than a solid coal block. Therefore there is also the warning not to clean potentiometers in ultrasonic cleaners. Modern pots may be chemically and mechanically robust (like carbon brushes for strong motors) and even certified with a guarantee to survive PCB cleaning solvents used in factories. But ancient potentiometers are a different cup of pee. If the track is of nitro or spirit laquer, then Rest In Pieces.

 

By the way, I have successfully repaired broken carbon tracks with conductive carbon paint based on such lacquers, those of course are not resistant to solvents either. Also a soft pencil can be used to patch a damaged carbon track, which isn't particularly stable either.

 

And the reason that in the test with DeOxit the knob rotates much easier is because the shaft bearing/sleeve intentionally contains a viscous grease (may be to stop dust and make it feel more solid) that likely got washed away. That grease tends to solidify/form resin over time which makes the knob hard to turn.

[534N]

@CYBERYOGI =CO=Windler- I appreciate your detailed explanation on this matter. I will be more careful when I finally disassemble my 400v and clean it. I'll stick to isopropyl alcohol and see where that takes me and try to find some lube to keep the pots protected and smooth. Do you have any insight on the lube part? I'm definitely interested in any other tips you may have.

[pianokeyjoe]

There is a cleaner with conductive lube that is used by YAMAHA Japan, that is used by them to clean and prep their instruments. ALso from YAMAHA, there is a white grease for the keys and other plastic parts that is used to this day for lubing the keybeds and other moving parts. I do not know how to read Japanese but I have only seen this in Japanese selling websites. Anyone have clues as to where to buy these outside Japan? Casio would using a version of these 2 things too. Casio parts used to be sold by Radioshack/Tandy Corp, but that was changed in the late 1990s sooo, Now what? @CYBERYOGI =CO=WindlerI have a MT65 with missing carbon on several keys contacts. I will try the pencil method and report back.

[CYBERYOGI =CO=Windler]

For lubrication of plastic parts I only use silicone based grease/oils. Any other fat/oil may decompose plastic over time (may take weeks or >10 years, but not suited for long term preservation). Thin silicone oil is good for fast spinning or very low friction parts (fan bearings, seconds-hand cog in quartz clock movements), but because it moves around/may evaporate, I use for slow moving parts a tube of "NASP SILIKONPASTE N.D.P. (no dropping point) - SILIKONFETT - SILIKON + P.T.F.E." (somewhat expansive but lasts long, found on eBay), which is a white grease that also contains teflon nanoparticles to distribute point loading (hence do not use it for water taps - that's nanoplastics). But there are warnings that silicone oil may damage silicone rubber (non-silicone oil dissolves e.g. latex rubber), so better keep the lube away from silicone rubber key/button contacts (not all are actual silicone, which complicates the situation). Otherwise some rubber contacts (e.g. under scratch disc in toy DJ consoles) are designed to be lubed and may quickly wear out when dry, so this is a "wash me, but do not make me wet" situation without a single correct solution. Also keep any lubes/oils away from Casio's infamous metalfree LCD foil cables. If in doubt (and nothing squeaks, gets stuck etc.) do not lube at all.

 

Do not fall for claims like "conductive" lubricant. Actual electrically conductive lube (e.g. graphite powder) would cause shortcircuits everywhere it spills  and is only useful for very special cases (high current motors etc. - definitely not analogue audio). Normal electric contact lube is designed such that metal/carbon contacts can still pinch through the grease film enough to conduct electricity, but it is not conductive by itself. The Yamaha white grease is likely a similar silicone based substance like "NASP SILIKONPASTE N.D.P."

Edited November 20, 2022 by CYBERYOGI =CO=Windler