Korg Cx-3 Version 2 Service Manual

[Ajochum]

I just purchased a Korg Cx-3 version 2 (2001) that doesn't produce sound in either the headphone jack or through the speakers. From earlier comments, it might need a motherboard. I haven't received the unit yet. In preparation, I'm searching for the service manual and hopefully the schematics for it. I've found both for the earlier model, but need the newer.

Does anyone out there have these items? I have an excellent person who might be able to repair it if he had the schematics. Many thanks in advance.

[WheelHead]

I have one too I bought super-cheap on eBay a few years ago. I need to take a look at it again when time permits. MIDI works on mine. You might want to try, if it powers up, to load the CX3 V2 firmware. It is still available on the Internet somewhere. Do at risk at making it toast if midi works.

 

I got mine to work by turning the power on and off quickly (not to suggest this) intermittently, rebooting fast, trying to get the chip that holds the sounds to load and to my surprise I could hear it through the head phone jack. It worked but turned-off it would not work again until I did this repeatedly again and then it would not load at all after successfully doing this several times or more, but it worked perfectly when the sound did load. Doing a reload of the firmware, all care should be given because, like I said, the unit may be usable for MIDI if MIDI works. A reload failure may make the keyboard 'toast' and kill the MIDI usability - my MIDI works perfectly as mentioned and I am considering making an HX3 organ out of it sometime- shame there isn't a cosmetically-nice kit like the XB2 kit to make an HX3 organ out of a CX3 digital - though it can be done self-styled.

 

When I tried reloading the firmware it was a bit tricky with USB MIDI (I used M-Audio Midi-to-USB) and I never turned it off until OS load was complete but it did cite a chip failure that would not write. Perhaps locating the micro-chip and having the chip re-balled may (though I doubt it) work. Korg does not sell pre-loaded chips for the motherboard to solder-on why there is a lot of them out there like this and didn't, imo, have many motherboards made. Those that were made, mostly, were used for incompetent OS upgrades where the owner made it unusable from a bad write failure and sent in to Korg to repair or a factory repair tech (way back in time when this could be done).

 

I took mine completely apart and cleaned all the cable connections and looked closely at the lands of the PCBs but after OS load attempts and the failure to write to a micro-chip it appears that is the problem.

 

I owned one a long time ago that worked perfectly I sold going into a Speakeasy Tube Preamp. When I heard it again through the headphones, I still liked it.

 

WH