Anyone out there who knows what might be wrong with a Roland KR500 built around 1989 ? Some notes play some don't. Took off all of the keys and springs, cleaned ou all the crud, dust, hair and used isopropol alcohol to clean off the circuit board. The most likely cause for non playing notes are worn out/wearing out soft contact switched under each key. They come in a
strip about every octave or octave & 1/2. A replacement set is $38 which I can buy directly
from Roland but they will not give out any technical support info over the phone. Take it to a service center they say- sounds like a big
charge to do that. So can anyone unofficially tell me if these contact switches are worth
trying next. Its sounds as if the notes are
trying to sound but that the switches/keys are
shorting out. I though of moving some of the switches around- like taking a strip that works and moving that to an octave that isn't working.
That way it could confirm the switches are at the root of the problem. The last guy that repaired this thing told the owner she could do this herself. I was able to get one guy at Roland to
tell me that the switches do wear out but he
clammed up when I said I was not a service center.

so, firt of all i want to apologize for bringing up a topic from 2003 , BUT i just would've ened up writing the same questions
because
i have the exactly same problem and i want to ask exactly the same questions as JIMBOB

So...please answer

I'm just guessing, but the keys are essentially
electrical switches and have a contact
point. Over 20 yrs. time, all kinds of debris
might have fallen between the keys and
crudded up the contact points on a
number of keys. So the solution might
be simply to open of the piano and
carefully clean off the contact points
of the keys that are non-functioning.
It might be obvious at a glance that
there is a difference in the contacts for the
keys that are functioning and those
that are not. Or, the contacts might
have been designed originally with too shallow
a seating, which would cause them
to lose contact after a time through
corrosion, etc.--so you'd need to
somehow restore the contact point, maybe
by roughening up the surfaces with
a file, etc. In any case, this would be a
tedious, painstaking job, and you
should not use any liquids
when doing it, because liquids are the
worst thing for a digital piano.
Also, there will be permanent grease
around the key mechanism, and you want
to preserve that as much as possible.

well, i cleaned up the inside of the piano...i used liquid(spirits), but not directly; i put some of it on a rag and then cleaned it...so, any other ideas?

And another problem, besides of a lot of keys aren't working, some other keys have high volume
And also i am from Romania, and i think i can't order electrics from eBay

This needs to be done with care and without
the use of any kind of liquid at any
stage of the process, as liquid will
instantly oxidize the metal surface and
create a barrier to electrical flow.
Despite warnings you've doused it with
liquid, which has only made things worse.
If you're not willing to take time and
care in this, and moreover, if you insist
on using liquids in the process, you're
wasting your time and you shouldn't even
bother.

This kind of repair of electrical items
that are normally of the remove-and-
replace-variety, is venturing into
unexplored territory and you need to
be innovative. The first thing is
to examine those keys that work and
to see how it is that they work, where
the electrical contacts are, etc. Then
for the non-working keys you need to
somehow reproduce the same situation
as with the working keys--the problem
is likely to be in the electrical contracts,
rather than inside the computer chips;
indeed, it would have to reside in the contacts
in order to be able to fix it.

If you find that the contact points
are absent in the non-working keys, is
there a way to restore the contacts? For
example, by cleaning (no liquids, not
even on a rag), gentle buffing,
shimming, or some other means.
And so forth.

The liquids that are bad for electronics are things such as soda, tap water (because of the added chemicals such as chlorine), kool-aid, iced tea, bud lite, etc. However, not all liquids are bad.

Theoretically, you could dip your entire keyboard in a tub of distilled water and it would work fine for many more years as long as you let it dry before plugging it back in. Liquids do not cause oxidation, and normally chemicals like isoprophyl alcohol are ok for electronics. I am unfamiliar with what's in spirits but I doubt it has had a negative effect on your key contacts. Sounds to me like it's just time for some new parts.

I used the rag with spirits before posting here, so about 1 month ago.

And, i don't know were to buy new parts from, do you?

Call Roland and see if they will send you the replacement part. You probably wouldn't need any technical advise for putting it in. Just getting to them is half the battle.

Hi, being technician I also have a KR-500, which had the same problems. I dismantled the keybord, cleaned all contacts carefully with silicon cleaner and found, that the problem lays there where the foil cables are glued together at the top and bottom end of the keybord. I had to tear them off, make a special contact comb and fitted it to a standard flat cable that is soldered on the end to the connector board. And it works better as new!! Anyone interested can ask for fotos by direct Email (dasabo@gmx.ch), dave

Here's an entirely new subject on which Gyro posts dubious claims!

Liquids provide a medium in which oxygen from the air can combine with metals in the electical conductors to form an oxide layer. Such a layer is less conductive than bare, clean metal. But the process is slow. As long as you dry things off, you won't have a problem.

Anyway, alexugoku says he used "spirits", not water, so the water thing isn't even relevant. He didn't say exactly what "spirits", though ... I hope it's not the type that dissolves plastic?

JIMBOB said he used isopropyl alcohol. It that's the kind you get at a drug store, then it's typically 70% alcohol, 30% water. But even with that water content, you can expect it to dry quickly. After all, you're just wiping with a rag/towel/Q-tip/etc, right? The wiping does the cleaning, and only a tiny film of liquid remains behind. It'll be complete dry in just minutes, perhaps seconds. Not a problem.

Sorry, alexugoku ... I don't know where to get parts. Did you look at the manufacturer's web site? They might have contact information for company resources (or third parties) that could help you.

JIMBOB, if you know that you can get the parts from Roland for just $38, it sounds like you have half the problem solved. If you don't feel qualified to do electronics work, perhaps you can find a local repair shop ... or better yet, a friend ... to help you. I can't say more because I can't see the parts you're talking about. But if you want to PM me, I might be able to provide some help.

Well, after two years I finally managed to repair the freaking thing. The problem wasn't the contacts at individual notes, but the contact that made the connection between the motherboard and the circuit of the notes.
The conducting material was interrupted or non-existent. So i bought a silver conducting liquid and draw it, and i also put something to keep the circuits thight.





So i thought that the problem was from cola or other sticky beverage that dissolved the circuit, until it got really hot in here and glue started dripping from the keys.


That glue was keeping the weight of the key. So I started to take out the weight from the key using boiling water, in order for me to glue them with something that won't drip and damage the circuits whenever it gets hot.



So now i have them separated, but i still can't get the glue removed form the individual pieces, and also from the piece that i first showed (Nr.3 picture) - I can use a hair dryer or boiling water again, but the glue is always creamy, so it doesn't entirely get removed-.
Do you know what that glue is and how to remove it? Is there a special solution that dissolves it? - I tried everything: spirits, acetone, diluent, water. It is very sticky, the color is pink and is slightly sweet.

Wow, now that's what I call commitment!

Actually, this looks like quite a fun project - do please keep us updated with this restoration.

Cheers,
James
x

Wow, this thread has some staying power!

Don't know but WD40 dissolves quite a few glues.

Love the repair photo's, a like-minded person.

Thank you, but the only reason i repaired it was, to simply put it, lack of money. (A digital keyboard with about the same characteristics - good key weight, good texture - was about 500 euros.)

And, as you will see, it wasn't really all that fun.



Thank you for the recommendation, it worked pretty good.

Do, I will.

As I said, i listened to spanishbuddha, being the only one who proposed something.


I then sprayed some WD-40 on the glue, and let the solvent get into the glue for about 2 days for half of the keys, and 5 months * for the other half - as you can see, i used a screwdriver to get the glue out; it was very, very boring and time-consuming, *so after I was finished for the day with one half, I didn't want to do it again any time soon; the solvent helped, the glue became less sticky, but it was no miracle-worker.


I did the same with the weights, but it was a bit easier, given the fact that those are almost 2D.


I then used Poxipol to glue the weight to the key. I used a little amount, as you can see; no more is needed. I then used the other end of the screwdriver to put some pressure.


As for the black keys, given the fact that those weights were glued to more than one side (the weight touches with 5 sides), it didn't fell. So i just used silicone to make barrier, so the glue won't drip.


As you can see, it worked pretty good, no more dripping. (I also used a little amount on the edges of the white keys, to cover the little gap - just to be sure.)

It was not worth it. If i knew from the beginning the amount of work-hours it would take, i wouldn't have begun. So for anyone who has a broken Roland KR-500... throw it out and buy a new one! I'm serious.

But now mine is finished! Finally.

The last touch was to remove the effects buttons, so i can push them with a stick; I know you're supposed to push them while you play, but they didn't work... so it's better than noting...




Now I can finally do what I've been waiting for 1 year... download some sheets from vkgoeswild and rock! \,,/

Congrats - great job!

James
x

Hey well done. I'd forgotten about this one. Congrats too, I admire your patience and persistence.