One key sound louder and does not respond when I
Keyboards that sense the dynamics of playing have two contacts underneath each key. One of those contacts is most probably a bit dirty.
To clean it, you need to open the piano housing, remove the faulty key (you may need to release the keyboard from the base), there are rubber (or another kind of) contacts, similar to those in a remote control. If they are rubber contacts, you need to clean them on the rubber side as well as the tabs on the board under the rubber button with a cotton stick and some ethyl or isopropyl alcohol (don't use acetone, benzene or similar strong solvents, you will damage the rubber).
If they are another kind of contacts (e.g. relay type - metallic, you need to clean them with very fine sandpaper.
That should do the trick, but if it doesn't, there is probably physical damage to the conductive rubber or tabs on the contact board. To repair the rubber contact itself you need repair liquid (e.g. for remote keys, which is actually made of some benzene, some rubber glue and some grapphite powder). You can make it yourself but you may need to experiment with the grapphite/glue ratio to get enough conductance for the contact to work properly. You'll get the grapphite dust by smearing a drawing pencil core over a piece of fine sandpaper.
If the contact tabs on the board are damaged, you'll need some "leitsiberlack" - silver repair liquid, this is a similar liquid that contains silver and makes a somewhat solid contact. (i'm not sure about sources for this, but in europe, it's sold by Conrad electronics under the name "leitsilberlack"). You need to apply some but take care not to connect the two halves of the tab or the key will not work properly.
I had a case of identical malfunction on a roland synth (it has rubber contacts) and the cleaning alone solved the problem entirely, hope you can solve it that way yourself.
Jul 22, 2009 |