Suddenly, all D, F# and A# notes are dead

Mezzopiano · Post by **Mezzopiano** » Wed Jun 19, 2024 6:40 pm

Hi, as the title suggest, my Kronos X 88 is acting weird

It sometimes begins working again if i hit the keyboard from below.

What could be the culprit?

I used to own a Kronos 2 that was acting weird (random transposed itself, pitch bending) and i fixed it disconnecting one of the boards and cleaning it with alcohol, no issues since.

I want to try this approach again with Kronos X, but id like to know where to clean. Maybe the flex? the keyboard board?

leland_iko_music · Post by **leland_iko_music** » Thu Jun 20, 2024 6:49 am

I don't own a Kronos (though I would love to be able to find a good condition Kronos2...)

Your comment about transpose/pitch-bend sparked my interest though.

On my PA5X, I have an issue where if I use the pitch-bend/articulation joystick, upon return to dead-center, the sound is often de-tuned by a few Hz (usually slightly flat). Since I do a lot of livelooping, it is a complete ear-sore when I have already several tracks/layers down and all of a sudden an instrument is out of tune compared to the rest of the tracks.

If I jiggle the joystick back and forth a few times, it MIGHT put it back in tune, but not always.

Any ideas if somehow cleaning the module might help ?

Leland

Dan Stesco · Post by **Dan Stesco** » Thu Jun 20, 2024 9:00 am

The PA5 is new enough for the potentiometer to be failed. Probably the nut that fixes the potentiometer to be weakened and the spring brings the joystick to a vertical position but the potentiometer does not stay fixed in its place so that tuning errors occur.

leland_iko_music · Post by **leland_iko_music** » Thu Jun 20, 2024 4:13 pm

Dan Stesco wrote:The PA5 is new enough for the potentiometer to be failed. Probably the nut that fixes the potentiometer to be weakened and the spring brings the joystick to a vertical position but the potentiometer does not stay fixed in its place so that tuning errors occur.

Thanks. I presume I can access the pots by removing the module by removing the 4 screws on the top corners of the joystick module? (and not have to unmount the side or bottom panels)

Leland

Dan Stesco · Post by **Dan Stesco** » Thu Jun 20, 2024 8:30 pm

Not open yet, will ask if have access on top.

Derek Cook · Post by **Derek Cook** » Sat Jun 22, 2024 6:14 am

99% of all the keyboard problems I have ever had are bad connections on the cables between boards, so that is the first thing I look for in a case like this.

Connections can oxidise/tarnish over time leading to poor contacts, and there is also another phenomena called "thermal creep" where heat induced expansion/contraction can cause connectors to very slowly work themselves loose.

yoshi88 · Post by **yoshi88** » Sat Jul 06, 2024 6:48 am

When multiple notes are dead across all octaves of your keybed, suspect the contact PCB's ,their linked connections and the ribbon cable connecting the keyd assembly to the motherboard.

I have had to replace numerous Contact PCB's ( Low, Medium and High boards on various YAMAHA and ROLAND products due to board faults such as faulty chips or contamination, connector + ribbon cable faults )

Sounds like an intermittent connection that you can check.

Mezzopiano · Post by **Mezzopiano** » Sat Jul 06, 2024 5:34 pm

Thanks everyone for their replies

We checked the keybed circuit board and found some issues with corrosion and some bad soldering, after fixing that the keyboard started to work better again

We still have a small problem when playing several notes (stacked chords) triggers some unwanted notes (Ab Major chords trigger middle D for example) so we suspect rubbers going bad