I hauled out my Hoover- it didn't do the trick

[Toril S]

Hello friends.

I recently read about people hoovering the keys.
Since I have a key that makes strange noise, and I am not adviced to blow air into the keyboard, I thought that it would do no harm to draw some dust out of the keybed.
Maybe that would do the trick? So I hauled out my hoover and did it! Yes, dust came out. Actually, some rather big grains of dust came out! The keyboard is cleaner now! But no magic happened, the key is still giving that loud sound now and then.
I have the canned air bottle in my hand, ready to shoot at the offending key with anger! But I will listen to my friends and go to sleep instead.
Good night everyone on this side of the globe

[mikf]

If your keyboard has a lot of dust and you blow it all over, there is always the risk of making things worse. But since you have vacuumed out a lot of dust, and still have the problem, I see little risk in trying the blower. Nothing much to lose. If it is a bit of remaining dust causing the issue the risk that you move it and it lands somewhere else equally critical is probably remote.
Mike

[Toril S]

Mike, I always cover it with a dust  cover, so I was a little surprised to feel some dust under the keys. My 18 years old 2100 never developed  any problems with the keys.Quality  is not what it was before!

[EileenL]

Maybe the rubber strips need replacing. They do wear after time on some keyboards.

[Toril S]

It is in the hospital now....

[GregB]

I had to replace a few rubber strips on my PSR-520 because of the same problem you describe.  I still have the PSR-520; my kids use it now.

When you press a key, it is actually two switches that make contact at different points as the key moves downward, and the keyboard measures the time difference between those switch closures.  That time difference provides the key velocity (volume) - shorter time means higher key velocity, as v = d/t.  Apparently, if the first switch never closes because of dust contamination or wear, the note will sound at maximum velocity (volume) when the second switch closes.

The switches are formed by carbon pads on a flexible rubber strip touching exposed traces on a circuit board.

In my situation, I found a for-parts-only PSR-520 and pulled a bunch of stuff out of it, including those strips.  I didn't analyze my S950's keybed too carefully when I had it open recently, but my impression was that it was a very similar setup.

I usually dust off my S950 using a handheld vacuum and a 3" wide paintbrush.

- Greg

[Toril S]

Thanks friends.