Szo Posted January 28, 2022 Share Posted January 28, 2022 Hi! i've recently buyed an very rare Casio CTK 1000 from 1993. Everything is working, except the keybed. I've got access to it by a external MIDI controller, but through MIDI you can't edit the sounds, which is quite important feature of this model. I would also like everything to work fine in this wonderful piece of gear. The keybed PCBs are totally rust, no hope for rescue. I need to two spare PCBs labeled: M615T-KY1M M615T-KY2M I found that the same was used in the CTK-750 (due to the service manual). I've got 750 but since it's fully working, don't wan't to discard it. Also close relatives from the same time are CT 700 and CT 770 - i wonder if they have the same PCB? There are no service manual or information on the web. I also found that CTK 650 (close relative to 750) have the PCB M616T-KY1M/KY2M - anybody knows if it's compatibile? Regards Quote Link to comment Share on other sites More sharing options...
pianokeyjoe Posted January 28, 2022 Share Posted January 28, 2022 Looks like you have found your own answer there. The thing to look at is the KEYS of the keyboard, and see if the keyboard model in question has the SAME keys(CT700 was the first unit to use those thicker keys with the bend or pivot point being thick molded plastic and the thin flexible part is hidden under the face. So the CTK1000,CTK750,CT770 and CT700 and, there are other models that look just like these mentioned models INCLUDING the CTK1000, that will have those same keys. All units are METAL keybeds and all units have 61 keys. Now.. RUST.. IS by chance, the RUST around the area where the BATTERIES would have been?? If that is so, you need to check for other damage as the battery acid leaked all inside you keyboard and other issues can and will arise. I found out baking soda and vinager can be used to neutralize the acid and clean it up. Try that on the key contact boards and see just what extent of damage you have and then go from there. But yes, if it is due to batteries leaking, the contacts may be eaten up, and you have no choice but to change the contact boards. OR... You may be able to substitute with another keybed with similar circuit layout. Any chance you could take some pictures of the damage? Quote Link to comment Share on other sites More sharing options...
CYBERYOGI =CO=Windler Posted January 29, 2022 Share Posted January 29, 2022 Casio tends to use printed conductive carbon paint for key contacts and wire bridges (actually acting as resistors), those get eaten away by battery acid (and likely by vinegar and baking soda too, so be careful!). They do survive water and dishwashing detergent, so take the keys PCB out and wash it. Also wash the rubber contact strip. Wash the soap off and dry it by hairdryer before putting things back together, Where key contacts are gone, try conductive paint or simply glue a piece of copper foil with soldered wire on the PCB to fix it. Also though-hole copper contacts in the PCB often get eaten by acid and need to be replaced by a wire bridge. Quote Link to comment Share on other sites More sharing options...
Szo Posted January 29, 2022 Author Share Posted January 29, 2022 (edited) Hi! Thanks for the answers. I think the format of the keys are not everything - keys may be the same in various models, but the metal frame and the keyboard PCB may be different. I can surely repair plastic contacts - i've done it many times with tv remote control repair kits. But the M615T-Ky1m and M615T-Ky2m PCBs are gone. No chance for repair. I've done it in the past in other cases using conductive paint or glued wires, but it was when 1 or 2 paths were gone. here 75-80% of the PCB conductive paths are rusted. I don't think it's not from the battery leakage - battery is ok. Maybe someone leaked a beer on keybed? I don't know. Also all the other things except keybed are working and have no signs of rust. I wonder if this PCB has to be be from the model with same polyphony (32) since the keyboard matrix. What do you think? I have chance to buy quite cheap broken ctk 650 but not sure if it gonna fit, because M616T-KY1M/KY2M may look different. Edited January 29, 2022 by Szo additional info Quote Link to comment Share on other sites More sharing options...
pianokeyjoe Posted January 29, 2022 Share Posted January 29, 2022 @CYBERYOGI =CO=Windleris right. The key contacts are done with carbon and not so much with copper so the vinegar and baking soda may not be right for those boards. You have to neutralize the acid somehow though, before working on circuits. Will soap and water alone do that? Or is there some other safe solution as the acid has to go FIRST before messing about with the electronics. I speak from experience at least with the Yamaha keyboards I have repaired recently. In the past I have used isopropyl Alcohol to clean those contacts with a swab but that did not always work if there was acid damage. I have a MT65 with a bad contact board that the carbon traces have come off completely and I would have to redesign and reprint a new circuit board.. While the software tools exist for free now in the open source world, I do not have the physical tools to make that a reality(too costly). What to do, what to do. Quote Link to comment Share on other sites More sharing options...
CYBERYOGI =CO=Windler Posted January 30, 2022 Share Posted January 30, 2022 (edited) When polyphony is higher than 2, the model does not matter. But the general layout (count of rows x columns) matters (most Casios use 6er groups) and if it has velocity (CTK-1000 does). If a PCB got massively damaged by battery "acid" (which is actually a lye in alkaline batteries) the epoxy may swell and become conductive. I read that soaking the spots in pure liquid dishwashing detergent for a day (cover it to prevent drying out) can help to neutralize the chemical. (I did this with an LCD watch.) Then rinse it with freshwater an towel it dry. (You may also use a hairdryer at low heat.) I have occasionally cleaned Casio PCB and rubber contact parts with a cotton swab and isopropanol, but do not scrub hard on those carbon traces. Also the carbon track in some potentiometers (e.g. 1980th Bontempi slide pots) can get damaged by isopropanol. Particularly NEVER spray "contact cleaner" fluid into them, which random solvent mixture is way too aggressive. Otherwise I got a very dirty Casio MT-70 which crackled like hell and made no sound in most potentiometer positions. Normally I would take the pots apart and clean inside, but in this model this needs to unscrew and remove half a dozen of stacked PCBs, which even is risky due to the flimsy LCD foil cable. So I gave it a try to slowly pry off the rotary knobs by screwdriver and pour isopropanol (better use 99%/waterfree one instead of generic 70%) down the shaft from the panel side. To make it flow down, I pushed an airpump hose around each shaft and pressed the airmat bellow to force the liquid into it. After playing decathlon on each of them (i.e. turning about 30 times in both directions while listening) the pots worked almost like new. Edited January 30, 2022 by CYBERYOGI =CO=Windler Quote Link to comment Share on other sites More sharing options...
Szo Posted January 30, 2022 Author Share Posted January 30, 2022 OK - here is how the other site of one PCB looks like. As you see, very bad. Don't know if there is another option for the rescue, than finding broken CTK 550/650/750/1000 or ct 700/770 (all of them have velocity, but only for 750 im sure it has the exactly same PCB on keybed...) "r. But the general layout (count of rows x columns) matters (most Casios use 6er groups) and if it has velocity " Also i think the problem if the shape of PCB is the same, because it can have holes for screws in another parts or different cable to connect to the main pcb Quote Link to comment Share on other sites More sharing options...
CYBERYOGI =CO=Windler Posted January 31, 2022 Share Posted January 31, 2022 Clean the rusty contacts with isopropanol and patch broken traces (watch for tiny black spots and use a multimeter) by soldering coil wires acros it. Conductive carbon paint can be cheaply ordered on eBay (from China). Its tiny plastic container has short shelf life and tends to dry out soon. To reuse it, you will need to add new solvent. Quote Link to comment Share on other sites More sharing options...
Szo Posted January 31, 2022 Author Share Posted January 31, 2022 my experiences with conductive paint is that it needs to have be thick layer, so it won't work here, as the traces on pcb are really small. i will trie with wires, but it seems to be a very difficult and precise task. I've recently got working CTK 550 which has M615T-KY1M and it doesn't fit. So i need to look for some broken cheap CTK 750 Quote Link to comment Share on other sites More sharing options...
pianokeyjoe Posted January 31, 2022 Share Posted January 31, 2022 18 minutes ago, Szo said: my experiences with conductive paint is that it needs to have be thick layer, so it won't work here, as the traces on pcb are really small. i will trie with wires, but it seems to be a very difficult and precise task. I've recently got working CTK 550 which has M615T-KY1M and it doesn't fit. So i need to look for some broken cheap CTK 750 Are you in the USA? If you are, are there pawn shops or fleamarkets or thrift stores near you? If I was able to have traveled to Florida this winter I bet you I would find any of those keyboards cheap and indeed find them period! I have a connection as it were, but she being a recent widow and an attractive one at that was not so willing to give me her number to be able to contact her to buy the Casios in one lot. So I would have to return down south. Sadly, that will not happen till summer now. If you have NOT fixed this issue by then, I will hunt down the keybed you need and we can talk then about remuneration for it. I was blessed by a member here back in 2014 or 2016 with a Casio CZ101 and SK1 so I think it only right to help another fellow Casio lover! Quote Link to comment Share on other sites More sharing options...
Szo Posted January 31, 2022 Author Share Posted January 31, 2022 Poland here. As i mentioned, i have fully working CTK 750 but i don't want to destroy it to repair CTK 1000. It would be a crime since CTK 750 is also very nice keyboard. I will wait for some broken 750. Good information it's not very rare here. I have even an option to buy another one CTK from my city for 75$ so maybe i'ts a matter of time when broken 750 will appear somewhere. btw im a little dissapointed by the quality of some (not all) voices both in CTK 750 and CTK 1000 - i found them inferior to the older Casio CT-X1 - which is the top of the line earlier series from 1992, similar to CT 670/680 but with reverb and chorus effects and famous green tone edits, also premium case. For example preset "Cathedral" is absolutely gorgeous choir pad in Ct-x1 and in ctk-1000 its way worse organ tone. Also piano sounds weaker in the CTK 750 comparing to CTK 750 (in CTK-1000 it sounds nice). Good that CTK -1000 have nice acoustic tone guitar, very dreamy. But in ctk 750 it lacks something. And it lacks the great syntheseizer feature. I wonder why they made a worse product in next generation - the velocity sensitive version of the CT-X1 would be really great. Quote Link to comment Share on other sites More sharing options...
pianokeyjoe Posted January 31, 2022 Share Posted January 31, 2022 @SzoAww! I wish I could have helped you but yeah too far to be economically feasible. But wow $75? That would be cheap as a spare parts keyboard. Understanding WHY you would buy it for such as I did and DO the same to this day with keyboards. The keybed would cost you that used from ebay as I have seen it in the past. Now crazy thing, I was working on my house thinking about your situation and it dawned on me that at least in the past I remember having a spare CT700 keybed.. I do not know if I still have it or if I sold it and just forgot. Eitherway you buying a good complete keyboard for $75 is a bargain! I would do that quick!! I bought 2 CTK519 keyboards cause one I keep and the other I would use to sell off the keys as spare parts for other Casio users since those keys fit a majority of 1990s PCM keyboards for BOTH the non touch response and touch response version keyboards! Now as for sounds and your question? Casio has been all over the place with their sound tech in the 1990s. Some keyboards for certain markets in certain countries are made different for such markets. In the USA MAINLAND we do not have some of the models available in EU/ASIA/MIDDLE EAST. As such the lack of quality or lessened quality in the CTK750 or CTK1000 vs the CT1-X which I never heard of or seen, is due to cutting corners in some things to release MORE products to specific markets. Honestly, what may be less quality sound to you may be just the sound some one else loves.. Casio has quirky sounds and features that seriously, are not universal across the planet. In Argentina the MT750 exists, but not in the USA Mainland. Also, the change in economy as of 1991 has caused ALL nations to do business with MAINLAND CHINA and have most of not ALL products manufactured or parts for products manufactured there.. The change of "Made in Japan" to Made in China was gradual but it has brought about a 2 fold situation:more economical access to once very expensive products, and more innovation and thus improvements in many products that otherwise would have stayed in a stagnated condition due to technology costs.. 1980s suffered that. For that whole decade Casio had only made a full on leap ahead into the sampling PCM keyboard tech in 1988. 1989 was the turning point for Casio to completely leave behind the old tech of the 80s(PD,SD,iPD,and Consonant Vowel synthesis)and go full PCM based. Your keyboards fell in the transitional time frame of Casio and Yamaha changing from sourcing their electronics from JAPAN to Taiwan and Hong Kong.. then in the late 90s, from Mainland CHINA as well. In the 2000s, Casio had a whole list of keyboards that as I look at the bottom of them in my studio, say made in China and the quality is mixed, but the sound tech is the same(PCM based). So it is not so much that they made better sounding products in the 90s or 80s and then suddenly inferior ones for the late 90s early 2000s, it is just experimentation with different techs and manufacturing techniques as well as material sourcing.. Fast forward to 2022.. Now the World KNOWs about where things come from and sourcing.. Casio has made improvements in many things since the 80s, and in some, they ,like everyone else, have cut corners in materials to cut costs, in order to make a $449 voice synth workstation keyboard available to the masses. Remember that your CTK1000 back in 1993 when I saw it in the store was $700USD or some price near that... So in short, the reason why the despirity in sound quality between seemingly close keyboard relatives is economics.. Quote Link to comment Share on other sites More sharing options...
CYBERYOGI =CO=Windler Posted February 1, 2022 Share Posted February 1, 2022 (edited) I once repaired a Casio PT-50 that was soaked in battery acid, so its chord button PCB apparently had an acid puddle under the rubber contacts and lost most though-hole contacts and carbon paint. The conductive carbon paint is mainly for key contacts themselves (so they won't oxidize), but also adhesive or glued copper foil (tinned with solder) may work sufficiently. Use thin enameled wire for the rest. I used conductive silver paint (had no carbon) which may corrode over time, but the center piece of most carbon contacts was still there and mainly the metal trace was gone. I don't know how even and reliable the key response will be (CTK-1000 has velocity), but patching such things together is possible. See here. There are plenty of black rotten spots on your traces, so I recommend to place the wires in different paths than the original physical layout. The logical layouts (seems to be groups of 8 interconnected by diodes) may be easier to follow by making the insulated wires cross each others. Edited February 1, 2022 by CYBERYOGI =CO=Windler Quote Link to comment Share on other sites More sharing options...
Szo Posted February 8, 2022 Author Share Posted February 8, 2022 (edited) Thanks for all the help, i finally bought another CTK 1000, fully working in nice condition for a very decent price. Very lucky, because it's quite rare. Edited February 8, 2022 by Szo 3 Quote Link to comment Share on other sites More sharing options...
pianokeyjoe Posted February 8, 2022 Share Posted February 8, 2022 2 hours ago, Szo said: Thanks for all the help, i finally bought another CTK 1000, fully working in nice condition for a very decent price. Very lucky, because it's quite rare. Congrats!! Yeah! Now you have a Spare parts back up unit too! Quote Link to comment Share on other sites More sharing options...
Szo Posted February 8, 2022 Author Share Posted February 8, 2022 yes but since my "good" CTK 1000 is in great condition i think i will sell the one with rusted keybed. Maybe someone will bring it to life. Quote Link to comment Share on other sites More sharing options...
pianokeyjoe Posted February 8, 2022 Share Posted February 8, 2022 5 hours ago, Szo said: yes but since my "good" CTK 1000 is in great condition i think i will sell the one with rusted keybed. Maybe someone will bring it to life. If ya feel you must, ya must Then you could buy another Casio model with that money lol! Quote Link to comment Share on other sites More sharing options...
Chas Posted February 8, 2022 Share Posted February 8, 2022 8 hours ago, Szo said: yes but since my "good" CTK 1000 is in great condition i think i will sell the one with rusted keybed. Maybe someone will bring it to life. Personally, I'd hold on to it because as you said, it's a rare model and you'd have a source of spares if the need ever arose. Plus as rare as the CTK1000 is, I doubt you'd get much for one non working. It's worth far more in spares than sold as non working with issues. Talking of which, I have a CTK1000 in my collection too, and really should dig it out and explore it again. It's an interesting keyboard for sure, what with its velocity keyboard and tone editing feature. I have so many keyboard and so little time! 1 Quote Link to comment Share on other sites More sharing options...
Szo Posted February 8, 2022 Author Share Posted February 8, 2022 Youre right, maybe i'ts reasonable to keep them both. The one with rusted keybed i've bought for less than 20$ including shipping. I bought the fully working one (and in beautiful shape, nearly mint) - for 50$ with stand included. It was just 10km from my home. Funny that both appeared in last two weeks. Before, i've looked for this keyboard for a couple of months, it fascinated me from the first time i saw it. Other Casio keyboards from early nineties like Casio CT 670 (and his siblings), CTK 550, or CT 700, are quite common in Poland, but CTK 1000 - very rare. It's mysterious and unique in many ways. I think it's rarity comes from the fact that it was quite expensive, propably top of the line in 1993? Uniqueness of this model is also strange because from the early 80-s until today so many Casios shared the same or nearly identical engine. And this one is so different from others! 1 Quote Link to comment Share on other sites More sharing options...
Chas Posted February 8, 2022 Share Posted February 8, 2022 Indeed it is unique! IIRC, it's also the only Casio to state that it uses the "IXA" sound source, strange that it was not mentioned on any other Casio. Apparently it MIGHT share some architecture with the unique and also quite rare VA-10 "Voice Arranger" keyboard. Quote Link to comment Share on other sites More sharing options...
Szo Posted February 9, 2022 Author Share Posted February 9, 2022 Yes! I of course read that posts by CYBERYOGI while looking for any info about CTK 1000. I've also had a VA-10 in the past (i've selled it to my friend) and find that the effects section has some similarities with CTK-1000. But VA-10 had more effects and there were even more crazy and more steps. VA-10 - is another strange, unique and mysterious Casio. 1 Quote Link to comment Share on other sites More sharing options...
CYBERYOGI =CO=Windler Posted February 9, 2022 Share Posted February 9, 2022 Most strange is, the CTK-1000 hardware looks like when it had been intended to become something else (a real synthesizer??) with completely different control panel. Look at the right side of the panel PCB with empty section and cable mess. It is wired to a daughterboard with external MCU NEC D78CP14CW (shown to the left of the mainboard) that has unused ribbon cable solder pads (kind of generic prototype adapter?, or for an omitted LCD or such things?) that may translate the input data to the main CPU. It would be exciting to analyze what it does and if it dumbs down a much more versatile serious synth that never got finished. (I have no time at the moment.) (I hope I didn't clog the forum too much with almost fullres PCB pictures. I already reduced resolution but tried to keep most of the traces visible.) 2 Quote Link to comment Share on other sites More sharing options...
Szo Posted May 3, 2022 Author Share Posted May 3, 2022 I've recently bought broken CTK 750 for ~22$ including shipping, so now i plan to repair the second CTK 1000 and later sell it or keep it as spare one, propably because i have way too many keyboards, and i wan't others to explore this unique keyboard. 1 Quote Link to comment Share on other sites More sharing options...
pianokeyjoe Posted May 3, 2022 Share Posted May 3, 2022 7 hours ago, Szo said: I've recently bought broken CTK 750 for ~22$ including shipping, so now i plan to repair the second CTK 1000 and later sell it or keep it as spare one, propably because i have way too many keyboards, and i wan't others to explore this unique keyboard. Very good! Congratulations! I hope you can fix it and get what you want for it. 1 Quote Link to comment Share on other sites More sharing options...
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