KORG X5D half of the keys don't work

[mfadic]

Hello,

I have a X5D with a problem where 3 keys in sequence work and the next 3 don't; it goes like this across entire keybed. Tried swapping cables and the problem remains, it's the same with cables swapped, so it makes me think the problem is on the mainboard.

Any ideas?

Thank you all.

[Mellontikos]

I believe those keys are rubber membrane contacts. They are probably dirty or worn out.

You have to take apart the keybed, and clean them with alcohol. If that fails to fix it, the next step is to use a repair gel called "CaiKote" on every single contact, and that restores the contact's ability to be conductive again.

[mike_h]

When there are non-working keys in a specific pattern such as that is, the problem is most likely to be in the ribbon cables that connect to the key bed.

Open it up and check that all wires in those ribbons are securely seated and clean on both ends. It's possible that one wire might not be where it should be.

If all are secure and the problem persists, then it is possible that somehow a trace on the circuit board might have become compromised.

Also check for a corroded or cracked solder connection on any of the joints that connect to the circuit(s) of those wires.

I have run into situations like what you describe. Traces do break and solder joints do go bad. Freakish things, but they do happen.

If all above fail, then it's a component failure...could be as simple as a diode...or not...

[JayB]

This rather sounds to me like the "Note R" setting in the GLOBAL menu page 02A. Setting this to any other setting but "ALL" results in every other key not working, a.k.a. three white keys work, four white keys don't work.