Tyros2 plays an additional note (F#3) when I play C3 & E3 notes

yes.+254720781215

Turn off "Casio Chord" &/or autoaccompaniment

Please add more information to improve help, does the amp just distorts in that particular note or teh entire sound is distorted? does the amp distorts at low volumes?

There is something resonating with that note frquency. Often the grille or wiring inside will rattle at certain frequencies. You need a sustained source of these frequencies to find what is causing the noise.

I would check your fingering... You MAY be late in hitting a particular note and the using auto chord... this can cause the problem. Another thing is if notes are hit with different velocity that can affect the sound. Sometimes certain voices have VELOCITY switching which actually changes the voice depending on the velocity you hit a note.

Make sure you are NOT in looping mode. Make sure you do NOT have effects such as reverb inline to the amp and speakers. This will cause an echo of the note.

In playing fast you have to make sure to release the note fully and let the key come up. These keys have TWO contacts that are used in the scheme to measure note velocity. If BOTH contacts don't open, the note will NOT re-fire. The second symptom you have written would be a characteristic if one of the disconnect diodes has shorted. These diodes direct the strobe signals that scan the matrix of key contacts to avoid other octaves responding when multiple keys are depressed including those in other octaves. Servicing of the unit is required. It is unlikely you have the tools to DIY this problem. ONE THING to try is to tip the unit and gently tap it to see if some debris MIGHT have fallen in that may be shorting some of the matrix connections.

Read page 135 regarding the note range settings. Look also for keyboard split information. You may have the keyboard set to NOT play notes in the top octaves for the particular voice you are using.

This is not something that spare parts would likely be needed for.

The first thing to determine is if in the piano mode that the unit first comes up in do you get this problem. If you do not, the UNIT is likely OK electronically. If you DO get the problem as a plain piano at start up, then one or more disconnect diodes (small 1N4148) are probably shorted. This is VERY uncommon occurence. These diodes are on the contact boards of the keys themselves. Contamination of metal such as a paper clip or metal shard could cause the same thing.

The Tyros II has MANY features and a lot of these create layers that fire other notes when using styles as part of the stylle rhythm.

The keyboard split features that allow the keyboard to act as three seperate ones can lead one to think there is a problem.

I have two Tyros I and one Tyros II and have worked on all of them as they were purchased as damaged and non-functioning. I have schematics on CD and those are available from Yamaha America parts dept in California. They are copyrighted but they will sell you the CD with schematics, etc. for about $15.

I can help you troubleshoot the problem if it really is a problem. The first thing is to see if problem exists in the piano mode at startup. If it does, then try each note in combination to establish a pattern. If a disconnect diode is shorted, you will find certain notes interact. You need to find which are OK and which causes problems... Defining the keys as problems in chords does not help as we need key numbers such as C3 or F#4. Do the searches ONLY using two keys at a time as a matrix problem cannot be diagnosed doing three at a time or more.

This would indicate a problem with the scanning matrix for the keys. I don't have my schematics handy right now, to analyze which part might be bad...

FIRST though, check the settings for the keyboard splits on the utility page that has the splits. I have had this get clobbered and caused an unwanted transposed voice to sound..

If you can find other combinations that cause the problem that would aid in pinpointing the exact cause.

This could be a bad disconnect diode or short or break on the keyboard contact board or even a cable between the upper and lower contact boards. (The keyboard contacts are actually split into two groups high and low).

Please be careful in opening the unit. There are lots of screws and some in wells in the back. There are different threads and lengths, Make sure they go back correctely. Be VERY careful of the ribbon cables and their orientation. ALSO the power switch leads are very short... I often remove the switch rather than try to take the leads off.

I can try to find my schematics but that will take a while. If you are not comfortable working on electronics, this is a problem for the shop.