Hi everyone,
Thank you all for your replies.
I have just re-boxed my SX900 and it is being sent back to my dealer tomorrow. First of all computec1349 I agree with you completely, noise has always been an issue on PSR S series keyboards, but at least in my experience an issue hasn't appeared this quickly. I really commend you for applying grease yourself and am a big advocate for the DIY method(I own a computer recycling and resale business), it is fascinating to me to see why this problem is occurring in the first place, it seems like a trivial manufacturing mistake to me! Maybe with your help we can devise a repair guide for other users facing this issue although I agree with Mike that nobody should be expected to dissemble such a new keyboard to rectify the issue.
Enildo, I am sorry to hear that you are having problems trying to get your instrument repaired. Having seen your previous post on the thread, I can't believe that the engineers say that there is no non-conformity in their product, I believe Yamaha should honour the warranty. As an advocate for the right to repair movement, I really don't think it would be fair for a warranty to be classed as void for reapplying grease to the keys but I understand that most people wouldn't feel comfortable opening up such an expensive and complex instrument (although it isn't that difficult to do). It would be awful if something was damaged in the process.
Panos, I owned a PSR S750 before this instrument and remember that the keys had a noise when they were played, the noise was nowhere near as loud as the SX900, and it was much more consistent between each key. The F# was definitely louder than the other black keys on the SX900. After filming the video I noticed that most of the keys had a 'clack' but most of them were mild (but most likely would have worsened over time). The white keys on the SX900 were perfect for me. In terms of how I played the keyboard to get the noise to surface I admit I was playing the keys a little harder than usual (but nothing ridiculous) playing the black notes with a normal soft touch would reduce the noise but it was definitely still present. I first noticed the issue when practising a chromatic scale. My Yamaha Electone EL60's keys still sound fine, all consistent, even if the keys were played in that manner. I haven't heard of Uncle Rodger before.
Rich, I am more than happy for that link to remain pinned in your comment. I really appreciate you uploading that video in the first place! It confirmed that my suspicions that my keyboard had the same issue.
Hopefully within the next week I will have another SX900, and hopefully it does not develop the same issue. However I must admit I am trying to remain pessimistic about it.
Just as a matter of interest, have any SX700 owners faced this issue? So far it seems that it has predominantly affected the SX900.