Casio CT-650 Not Working

[Dakota67]

Hello

I have a Casio Tone Bank CT-650 from I think 1989. I got it passed down from a relative back a while ago and everything worked fine on it then, but now pretty much everything does not work. The only thing that works is the default piano sound when you turn it on. The Tone Bank control doesn't work, the rhythm stuff doesn't work, none of it. I would greatly appreciate some help as it has some very unique sounds that I just love. Thanks!

Edit: Now when I switch the Chord/MIDI switch, it will change the sound from the default piano to different ones. Very strange.

[Jokeyman123]

Often in my repair work-when any electronics device sits un-powered for a long time-or sometimes not so long-the capacitors will dry up-there are materials in the bigger caps that are a type of paste that  will last a long time as long as some power is applied to the circuits but can dry up and short out-break a circuit if no power is applied for a long time. Just a guess as to what might be wrong. Short of taking it apart and checking to see if any capacitors leaked-that can be visible-try keeping the keyboard on under power for a few hours, and see if some of the functions start to work. If the caps are dry, just applying power might rejuvenate these if that is the malfunction. Why I keep my old Equinox and other older keyboards on almost every day for an hour or so. There is also a possibility that one or more of the cables inside have crept loose-wouldn't take much for a ribbon cable to move out of a socket to cause major malfunctions-although I haven't seen inside this particular model which may be all hard-wired. At least the piano works-which means it is not totally bonkered. and buttons can also become non-fiunctioning diue to oxidation from sitting depending on theenvironment this was stored in. exercising the buttons or carefully using some pro anti-oxidizing cleaner carefully around the buttons might work. I use De-oxit for metal contacts, but careful around the plastic. Might have to get inside the keyboard to really clean the contacts used for the buttons, but you might get lucky if you can get some De-oxit or similar from the outside into the buttons.

[J.orion]

I’m looking for help with mine too. It’s definitely not something deoxit is needed to fix. It’s gotta be a power issue of some kind cuz if I turn it on while holding some of the tone selectors they do work consistently but not all of them. Of course not the ones I want lol

[J.orion]

Wish there was a factory reset type of thing I could do to it. 

[Jokeyman123]

J. Orion-are you using the original Casio power supply? i recently noticed-there are a huge number of cheap "replacements" on the market-flooding eBay, amazon everywhere I look. I needed a replacement supply for one of my Privias-and was astounded to see-there are almost none of the real Casios available now-must have something to do with the pandemic-and the ones I found, the one I needed-$30-50 for a real Casio supply. I mention this because unless you have one of these-which are substantially more powerful and well-made than the cheap replacements-it may not supply enough "juice" or power-you need to look at the amp rating-Casios need at least 1.5 amps-plus of course the correct voltage-and the right polarity-alot of these cheap replacements do not have enough 'amps" to run a Casio properly-and don't even say whether the barrel plug is tip negative or positive-for example, my PX560/350 need tip positive 12V-as is pretty typical-but many of the older Casios need tip negative as do so many of the Rolands-such as my older PX575 and many of the older CTK's. Assuming you have a good Casio supply-also can deteriorate over time if not used-although I've never had a Casio fail. Like the keyboards-the supplies have caps inside that can dry out if not kept "refreshed" by plugging in once in awhile. if you know how-check the voltage coming out of the power supply barrel plug with a simple multimeter-good to have anyway-I use mine for checking batteries, power supplies etc. A marginal supply will get a keyboard to work-but the tricky part is that it will malfunction if the supply is poor. Even a spotty partially conducting wire inside these barrel plug connections can cause weird problems-the molded plugs can disconnect inside without you realizing it buried inside the rubber barrel plug. It happens. some voltage will get through-but not enough to get the keyboard to work fully. As a tech, first hing I was trained to look for-problems in the power supply.

[pianokeyjoe]

As Jokeyman123 said, check that power supply! The older Casiotone uses a NEGATIVE TIP(center) 9VDC 600mA or higher mA rating to allow the built in speaker AMP to work without the keyboard power led pulsing everytime you play the thing. But in your case, I highly suspect the BATTERY compartment! Please check the battery compartment for battery leakage! That would be acid stains, rust and corrosion. Then you need to remove the back cover and inspect the area where the batteries would normally be and check the circuit boards for battery acid leak corrosion on the circuits themselves. You will SEE and KNOW that you have a problem, when you see oxidation and corrosion ON the circuit boards. I fear, if your CONTROLS are acting up too, that you have extensive battery acid damage. The other thing would be another likely scenario: spillage. If this board was used by KIDS, it has more than likely suffered Soda or Juice or Milk or Water spillage on the controls. So you will need to dismantle the complete keyboard(like they do in remanufacturing plants), and clean and deoxit all the boards and clean the rubber contacts for the controls AND the keys too. At least with a spillage, chances are your board will be just fine after refurbishing it. If it is battery acid leak damage to the boards and the delicate circuits? You may be in trouble there. But check for those 2 things in addition to the power supply. ALSO the proper CASIO 9VDC negative tip PSU has a tiny center hole to match the thin center pin in the Keyboard's power socket. Ah! And check the power socket is not "loose"! If it is, fix it. If you are handy with a soldering iron and wiring, you can jumper the solder points ON the jack itself to other points near the socket IF by chance, the jack is loose and the traces under the socket terminals came loose from the circuit board itself.