On 12/11/2014 10:16, Gareth Magennis wrote:
"Arfa Daily" wrote in message
...


"Gareth Magennis" wrote in message
...


"N_Cook" wrote in message ...
On 12/11/2014 08:30, Gareth Magennis wrote:


"N_Cook" wrote in message ...

Loss of pianisimo ? (heavy key press only to activate) on 2 keys. That
area schema/views not on elektrot. 2 contacts per key?, one worn or
dirty per key?




Nearly always due to dirty or worn key contact rubbers. These are
usually in octave strips available from the manufacturer.
Don't bother trying to repair these with paint etc. Really.
(Sometimes its just due to dirt - tobacco, pet hairs etc which can be
cleaned off)

Each key has 2 contacts, one hits the PCB before the other, the time
difference calculating the speed of impact, and thus loudness of note.



Gareth.

Assuming if not just grime, I have a large collection of zapper contact
sheets, to cut a couple of dimples from, and give them a go




No, no, no, no, no, no, no, no, no, no, no.
Really.


I knew that was going to happen.

Gareth.


Oh ye of little faith, Gareth. I'm sure he would be able to make them work
again nearly like new by coating with foil from a cigarette packet, or if
it's a *really* professional unit, Bacofoil ... :-)

Arfa


There are a few issues he

1. This is a piano, and piano players hit keys HARD.

2. The structure of the key contact strips is such that the shape of the
moulding is the "sprung piston" that ensures both contacts land straight and
accurately onto the PCB so the velocity of the key can be accurately
measured. You cannot cut these things without destroying that keys piston
and the ones around it that rely on their neighbours to keep its structure
shape intact.

3. Mending these things with paint etc might work for a day or so, then
your customer will think you are a Klutz for mending it instead of replacing
it and charging money for labour instead of a cheap new part.

4. You can buy them from the manufacturers for a few pounds.

5. Give number 4, why on earth would you consider 2 or 3 unless the part
was no longer available?




Gareth.



I doubt it, the owner did not know 2 keys were half-working, presumably
he used it like a mouse-organ (ala Python), from my preliminary on
receipt testing.
It came in because of idiotic Jalco type 1/4 inch sockets with no
mechanical fixings, I will not be replacing with Korg approved crap,
standard conventional sockets will go in there mechanically fixed so
they do not flop about.