Korg SP 250, electric piano

[N_Cook]

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?

[Gareth Magennis]

"N_Cook" wrote in message news:m3v46u$ced$1...@dont-email.me...

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.

[N_Cook]

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

[Gareth Magennis]

"N_Cook" wrote in message news:m3v64r$krd$1...@dont-email.me...

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


I knew that was going to happen.

Gareth.

[Arfa Daily]

"Gareth Magennis" <gareth....@ntlworld.com> wrote in message
news:6oF8w.1176982$xb.8...@fx08.am4...

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

[Gareth Magennis]

"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:8iG8w.871147$ck2....@fx17.am4...

There are a few issues here:

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.

[Arfa Daily]

"Gareth Magennis" <sound....@btconnect.com> wrote in message
news:_6WdndM-OYPrrv7J...@bt.com...

*We* know that, Gareth ...

Arfa

[N_Cook]

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.

[N_Cook]

I liked the potential booby-trap of the interboard connector, don't
remember seeing that type of breakable union before.
I was surprised how clean the contacts and pcb pads were. I'll go with
the single fine blonde hair looped under the octave silicone sheet,
though not directly over the pads when I got to them , it was looped
around the 2 affected key positions, melded to the outer flange of the
silicone. The pads , moving and static and diodes,traces etc all test as
expected, otherwise. alance of probabilies goes with hair. It would be
quite an achievement to fudge up a conductive pad replacement. The
stepped arrangement of paired pads would not be a problem but that very
squashy , ie thinned silicone , of the pedastal of each pair would be
next to impossible to work-around, I assume they can split at that place
, with heavy use or over time.

[Gareth Magennis]

"N_Cook" <div...@tcp.co.uk> wrote in message
news:m3vsnk$m6l$1...@dont-email.me...

Hairs, usually animal, are a common cause of failure here.

I might have seen one or two splits in my long time repairing these, but
usually the contact patches wear out long before they start disintegrating.
It is quite easy to split a perfectly good one when removing it from the PCB
though, if you grab the "pedestal" instead of the more robust edges.

Some (Roland) are quite tightly held in place with oversize conical silicon
barbs pushed through holes in the PCB, most just have interference fit
silicon cylinders that push into holes in the PCB, which usually have a
small hole in so you can use the wire from a ceramic power resistor to push
them fully home.


Gareth.

[N_Cook]

If a 50 micron hair is enough to block a function, it looks as though
the moving contact pads are too hard. I wonder if they harden-up with
age or use.

[et...@whidbey.com]

Greetings Arfa,
I'm in America. I have never heard of "Bacofoil". Is it just aluminum
foil? I know that we share many products that go by different names.
But then there are a few products that we don't share with you folks
on the other side of the water. Like Marmite, for example. I can buy
Marmite here, but I won't.
Cheers,
Eric

[Gareth Magennis]

wrote in message news:l8476a5mbod6rmiat...@4ax.com...

Eric, Marmite is really good for adding to a gravy that is a bit sweet,
fatty, or otherwise insipid or just not wide enough.
You only need a little, though. (If you can taste the Marmite you've put
too much in)
It can really open the whole thing out.

Anchovy does similar things to food that requires "something more to liven
it up but I don't know what".
Again you don't want it tasting of Anchovy.




Gareth.

[N_Cook]

What kids not raised on marmite soldiers in the states?
I like marmite but cannot stand the oz supposed equivalent vegemite , it
has celery in it or something like that.
What I don't understand is why something that the processors get paid by
brewers to take away, as a waste product, ends up in the shops 10 times
the price of similar size jars of mustard , that those processors have
to pay farmers to produce the main ingredient.

[N_Cook]

On 12/11/2014 17:01, et...@whidbey.com wrote:

More generally is it a litigious USA thing. In the UK we are quite happy
to refer to a hoover or selotape or Stilsons or Mole-grips or Jubilee
Clips or veroboard or whatever, instead of a generic term

[Michael A. Terrell]

N_Cook wrote:
>
> More generally is it a litigious USA thing. In the UK we are quite happy
> to refer to a hoover or selotape or Stilsons or Mole-grips or Jubilee
> Clips or veroboard or whatever, instead of a generic term

Bullshit. The generic terms are used, because there are so many
brands. If you've never been to the United States you have no idea of
its size. A lot of brands are regional, so someone outside of that area
wouldn't know what you were talking about.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

[et...@whidbey.com]

Oh, I don't think that's quite accurate. We ask for a Kleenex when we
want a tissue, a Q-Tip when we want a cotton swab, a Cresent wrench
when we want an adjustable wrench (spanner to you), Vise_Grips when
we want locking pliers, etc. By the way, I think Mole Grips are the
equivalent of Vise-Grips. Which of course means they grip very hard.
Have you ever been gripped by a mole? All the moles I have seen are
small creatures with small appendages. I can't imagine they have much
grip.
Eric

[Arfa Daily]

> Greetings Arfa,
> I'm in America. I have never heard of "Bacofoil". Is it just aluminum
> foil? I know that we share many products that go by different names.
> But then there are a few products that we don't share with you folks
> on the other side of the water. Like Marmite, for example. I can buy
> Marmite here, but I won't.
> Cheers,
> Eric
>

Yep, just ally foil, usually shiny on one side and dull on the other.
"Bacofoil" is just one of the original trade names associated with the
product over here. Anyone my age will just call it Bacofoil in the same way
as just about any vacuum cleaner gets called a "Hoover".

Just as a matter of interest, why would you not buy Marmite ? Is it just
that you don't like the taste ?

Arfa

[Arfa Daily]

<snip>

By the way, I think Mole Grips are the
> equivalent of Vise-Grips. Which of course means they grip very hard.
> Have you ever been gripped by a mole? All the moles I have seen are
> small creatures with small appendages. I can't imagine they have much
> grip.
> Eric

Check out

http://www.garagejournal.com/forum/showthread.php?t=76374

which will explain part way down where the name comes from ...

Arfa

[N_Cook]

Back to piano and forte.
Is there a recognised technique with perhaps a modified air duster to
get under an affected key and the contacts area and only requiring
removing the top "hearth surround" cover perhaps, for shifting non
grimey guunge, as an at-venue emergency temporary fix?

[ScottWW]

>wrote in message news:j2o76apssaae6hu6k...@4ax.com...

While not the source of the common name of the self-locking pliers, those
small creatures with small appendages evolved to travel _through_ the
ground; they are surprisingly powerful (or is it 'surprizingly?') when held
in the hands.
Scott

[et...@whidbey.com]

I tried Marmite and just plain didn't like it. A store called "The
British Pantry" that I used to live near sold it. They suggested
spreading it on crackers. I tried it and decided not to try it again.
This is not to suggest that I don't like different things or strong
tasting stuff. I make several types of Thai curries and one ubiquitous
ingredient called for is fish sauce. I bought some, opened the bottle,
and the smell of rotten fish almost gagged me when I stuck my nose
over the bottle and breathed in. The curry I was making called for 1/4
cup of the stuff but the smell was so bad I only used 1 tablespoon.
The curry just didn't taste right until I used the proper 1/4 cup
amount. Maybe I need to put Marmite in something to flavor it. Thanks
for identifying Bacofoil. The reason for a dull side and a shiny side
is because the foil is rolled as two sheets which are separated after
rolling. The shiny side is the side facing the rolls. Thanks for
posting the link too.
Eric

[Arfa Daily]

> I tried Marmite and just plain didn't like it. A store called "The
> British Pantry" that I used to live near sold it. They suggested
> spreading it on crackers. I tried it and decided not to try it again.

Ah, OK. It is definitely an 'acquired taste' but kids here tend to be
brought up on the stuff - maybe not so much now as in the past though.
Marmite themselves make a big thing of its 'bipolar' reputation - you either
love it or hate it, there's really no in-between ground. They have even run
adverts showing people hating it.

I wonder what sort of crackers they were recommending that you put it on ?
Most of the crackers that I've bought over there when visiting, would not be
very suitable. Ritz-style ones would be a definite no-no, and it's not very
good on things like cream crackers or water biscuits either. I wonder also
if they told you to put it directly onto the crackers, because that is a
no-no, as well. You must have butter on the 'substrate' first. You can just
about get away with butter substitute spreads, but 'straight' butter is
best, and not the whipped stuff if you can get unwhipped.

A good place to start with Marmite, is on white bread. Not any of the
'sweet' varieties that are common in the U.S. If you can get a plain white
fresh-baked crusty loaf, all the better. Spread with butter first, then with
the Marmite - and keep it thin. Personally, I pile the stuff on with a
trowel, but that's because I've been eating it for 55 years !

Many people like it on toast. I'm not a great fan of that, but same again -
butter first. As for 'crackers' its rye crispbreads that you want really. A
common one here is Ryvita and I think you have that your side of the pond as
well. If not, I'm sure there is an equivalent. Again, a decent layer of
butter first, then a thin layer of Marmite. If you do decide to try again,
using it for a cooking flavouring, just try it as described on bread on
crispbread while you're at it. You might just be pleasantly surprised ...
:-)

Arfa