briefer

That green thing in the photo seems like a voltage regulator, and they always run hot (at least the ones built in the 80s). You should check the service manual (as Chas mentions) to see the voltage that should be delivered by that regulator. Maybe the faulty part of the keyboard depends on it. Edit: nevermind, that green thing it is a transistor (2sb507f). Did you check the resistor with your multimeter? Link to the service manual: https://www.synthxl.com/wp-content/uploads/2020/04/Casio-CT-405-MT-65-68-Service-Manual.pdf

Maybe you can check if any resistor is hot by touching them, with the keyboard powered off.

May be a dead capacitor, you can desolder and check them. But is is a lot of work. I have an MT 65 with the same symptoms, but if I leave it powered on it works after a couple of minutes, Typical of a faulty capacitor.

Maybe if would be easier to install some DAW software and use your LK via MIDI

I would charge the batteries by removing them and using a charger like this one: As an alternative, you could also add a charge circuit to the package: and charge them with a USB charger, but that would make the connection more complex, as you should take cell balance into account. cheers

Hello I would like to share this desing I have created to adapt 3x18650 lipo batteries to a keyboard that uses 5xLR20 batteries. It uses a buck converter to adapt the voltage from 11.4v to 7.5v https://www.printables.com/es/model/706416-lipo-18650-to-lr20-battery-adapter I splitted it to make it possible to be printed with a regular 3d printer, and also to make it easier to put it in inside the keyboard battery bay. cheers

I have several spectrum in my collection, so I will try with the real hw If it works, I will create a video in youtube. Thanks!

Hi all I was surprised to find this little program to use the spectrum as an alternative for the MT-1 barcode reader pen and the MT-70 or VT-5: http://www.users.globalnet.co.uk/~jg27paw4/yr04/yr04_29.htm (I used an emulator and the code works, I did not try connecting the PC with the keyboard. Yet.) Is there anything more "modern" available to use a PC or smartphone? cheers

Yes ,you are right! Such a pity there are so few units of that model around...

Mmmh Mmmh not really, I do not think that model can save data to tape. Thanks anyway.

Hi, Just curious. Was there any electronic keyboard that used cassette tape as storage for songs, as with the ROM cartridges? Not for audio, but for data storage. cheers

Thanks, that is what I supposed. cheers

Thank you, I know how to use the usb memory to play midis, but my question is if it is possible to record from external midi devices.

Hi all I am using my LK S450 connected to my PC sith Synthesia and it works great. But I would like to practice without the need to have my keyboard connected to my PC, tablet or smartphone. Is there a way to record the songs generated by the PC in the casiotone? Thanks