The Kawai & Teisco Analog Synths Group

Hi,

I'm new here so my post might be repetitive but bear with me just a 
minute;)

I have tiny experience working with Korgs; Polysix, Poly-61, Poly-
800. I know what a non-rechargeable lithium battery is, I know what a 
rechargeable Ni-Cad battery is, I know the modifications needed to 
install a lithium in place of an old Ni-Cad, I've resoldered these 
things many times, so I do have some insight as to these matters.

I bought my SX-240 in perfect condition - the original battery did 
not leak. But, being preventive, I decided to replace it with a new 
one. First I tried a Ni-Mh battery. Then I used a NiCad. Everytime 
the result was the same: after some days Kawai was losing its memory. 

Finally I opened it, connected the battery circuit to a volt-meter, 
and what I found was this: When I switch the synth on, the battery is 
being charged in a fashion that seems perfectly OK, reaching 3,6V. 
But the moment I switch the synth off, it starts to fall down very 
fast. From 3.6V to 3V in the first 30 seconds and then from 3V to 2V 
in the next couple of minutes. You know what's next...

What's the matter ? What is killing my batteries ?
And what battery should I use in the place of the original one? A 
NiMh or a NiCad ? Does anybody have the battery circuit diagram for 
SX240 ?


thanks 
aero

---
The battery if charged should last about 30 days for the original.
Must be powered on to charge. If after charged your battery is quickly
discharged something is wrong. I used an equivelent radio shack cell
phone rechargable battery and it worked fine. If you modified yours to
take a different battery, that is over my expierence.(of course the
charging voltage will drop once turned off)


















 In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> wrote:

>
> Hi,
> 
> I'm new here so my post might be repetitive but bear with me just a 
> minute;)
> 
> I have tiny experience working with Korgs; Polysix, Poly-61, Poly-
> 800. I know what a non-rechargeable lithium battery is, I know what a 
> rechargeable Ni-Cad battery is, I know the modifications needed to 
> install a lithium in place of an old Ni-Cad, I've resoldered these 
> things many times, so I do have some insight as to these matters.
> 
> I bought my SX-240 in perfect condition - the original battery did 
> not leak. But, being preventive, I decided to replace it with a new 
> one. First I tried a Ni-Mh battery. Then I used a NiCad. Everytime 
> the result was the same: after some days Kawai was losing its memory. 
> 
> Finally I opened it, connected the battery circuit to a volt-meter, 
> and what I found was this: When I switch the synth on, the battery is 
> being charged in a fashion that seems perfectly OK, reaching 3,6V. 
> But the moment I switch the synth off, it starts to fall down very 
> fast. From 3.6V to 3V in the first 30 seconds and then from 3V to 2V 
> in the next couple of minutes. You know what's next...
> 
> What's the matter ? What is killing my batteries ?
> And what battery should I use in the place of the original one? A 
> NiMh or a NiCad ? Does anybody have the battery circuit diagram for 
> SX240 ?
> 
> 
> thanks 
> aero
>

Hi,
No, I didn't make any modifications.
The synth & circuits are in original condition.
30 days? What are you saying? Can't be.
The voltage should suffice for like couple of months...
I also used a panasonic phone cell for my Korg Poly61 and it works fine.
I know that the voltage drops off when synth is unplugged, but come 
on... here it's gone after 2 days! :(




--- In kawai_analog@yahoogroups.com, "texhand" <texhand@...> wrote:

>
> ---
> The battery if charged should last about 30 days for the original.
> Must be powered on to charge. If after charged your battery is quickly
> discharged something is wrong. I used an equivelent radio shack cell
> phone rechargable battery and it worked fine. If you modified yours to
> take a different battery, that is over my expierence.(of course the
> charging voltage will drop once turned off)

You should place a diode in reverse in front of the positive side of 
the battery so it is NOT charged (search in the forum as regards for 
how to do that). Use a Lithium.



--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 
wrote:
>
> Hi,
> No, I didn't make any modifications.
> The synth & circuits are in original condition.
> 30 days? What are you saying? Can't be.
> The voltage should suffice for like couple of months...
> I also used a panasonic phone cell for my Korg Poly61 and it works 
fine.
> I know that the voltage drops off when synth is unplugged, but come 
> on... here it's gone after 2 days! :(
> 
> 
> 
> 
> --- In kawai_analog@yahoogroups.com, "texhand" <texhand@> wrote:
> >
> > ---
> > The battery if charged should last about 30 days for the original.
> > Must be powered on to charge. If after charged your battery is 
quickly
> > discharged something is wrong. I used an equivelent radio shack 
cell
> > phone rechargable battery and it worked fine. If you modified 
yours to
> > take a different battery, that is over my expierence.(of course 
the
> > charging voltage will drop once turned off)
>

What I would do is solder in a lithium 3.6v aa sized battery with leads then connect a dvm in current mode in series with it (do not pwr the unit up). You

You can simply take off the original battery, then attach a coin cell
type lithium in a coin type battery holder (like the ones
motherboards have) using double sided adhesive tape, connect the
cathode (negative side) of the holder just to where the original
battery cathode goes, and the anode (positive side) to a diode
(positive side of the 1N4148 diode facing the positive side of the
battery). Negavite side of the diode goes to the 1.5K resistor,
originally connected to the battery.




--- In kawai_analog@yahoogroups.com, "Travis Shire" <boardjunkie@...> 
wrote:
>
> What I would do is solder in a lithium 3.6v "aa" sized battery with 
leads
> then connect a dvm in current mode in series with it (do not pwr 
the unit
> up). You can read the current draw from there and determine if
> something's drawing too much current. It should be just a few 
microamps.
> I don't have my 240 service manual here (moving, bah!) so I can't 
make
> other suggestions at this time. My 240 works just great with the
> lithium/diode arrangement.
> 
>   ----- Original Message -----
>   From: "sputnik979"
>   To: kawai_analog@yahoogroups.com
>   Subject: [kawai_analog] Re: SX-240 memory problem
>   Date: Tue, 01 Aug 2006 14:12:37 -0000
> 
>   Hi,
>   No, I didn't make any modifications.
>   The synth & circuits are in original condition.
>   30 days? What are you saying? Can't be.
>   The voltage should suffice for like couple of months...
>   I also used a panasonic phone cell for my Korg Poly61 and it works
>   fine.
>   I know that the voltage drops off when synth is unplugged, but 
come
>   on... here it's gone after 2 days! :(
> 
>   --- In kawai_analog@yahoogroups.com, "texhand" <texhand@> wrote:
>   >
>   > ---
>   > The battery if charged should last about 30 days for the 
original.
>   > Must be powered on to charge. If after charged your battery is
>   quickly
>   > discharged something is wrong. I used an equivelent radio shack
>   cell
>   > phone rechargable battery and it worked fine. If you modified 
yours
>   to
>   > take a different battery, that is over my expierence.(of course 
the

>   > charging voltage will drop once turned off)
> 
>   
> 
> -- 
> ___________________________________________________
> Play 100s of games for FREE! http://games.mail.com/
>

The charge current is very low on these instruments. You need to leave
your synth on for 1 - 2 days and that should help keep the charge up
for a longer time than 2 days. This is the reason why I charge my
NiCds before I install them.

I bought three as I was not sure of the symbol. Which one of these 
should I use? (if any...) Check out the pic:
http://img218.imageshack.us/img218/5844/clipboardof5.jpg
Can I use more than 1 diode in case one breaks down, for greater safety?
cheers
aero


--- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@...> wrote:

>
> You can simply take off the original battery, then attach a coin cell
> type lithium in a coin type battery holder (like the ones
> motherboards have) using double sided adhesive tape, connect the
> cathode (negative side) of the holder just to where the original
> battery cathode goes, and the anode (positive side) to a diode
> (positive side of the 1N4148 diode facing the positive side of the
> battery). Negavite side of the diode goes to the 1.5K resistor,
> originally connected to the battery.

Whau does the smallest says ? (it should be written on two seperate 
lines in very small letters)


--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 
wrote:
>
> I bought three as I was not sure of the symbol. Which one of these 
> should I use? (if any...) Check out the pic:
> http://img218.imageshack.us/img218/5844/clipboardof5.jpg
> Can I use more than 1 diode in case one breaks down, for greater 
safety?
> cheers
> aero
> 
> 
> --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > You can simply take off the original battery, then attach a coin 
cell

> > type lithium in a coin type battery holder (like the ones
> > motherboards have) using double sided adhesive tape, connect the
> > cathode (negative side) of the holder just to where the original
> > battery cathode goes, and the anode (positive side) to a diode
> > (positive side of the 1N4148 diode facing the positive side of the
> > battery). Negavite side of the diode goes to the 1.5K resistor,
> > originally connected to the battery.
>

uhhmmm.... 

IN
4I
48
RK

I guess...

Also another question - can I mount two of these diodes in a row, just 
for greater safety, in case one goes off ?


--- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@...> wrote:

>
> Whau does the smallest says ? (it should be written on two seperate 
> lines in very small letters)

I can't say, maybe someone else will be able to answer this :)


--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 
wrote:
>
> uhhmmm.... 
> 
> IN
> 4I
> 48
> RK
> 
> I guess...
> 
> Also another question - can I mount two of these diodes in a row, 
just 
> for greater safety, in case one goes off ?
> 
> 
> --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > Whau does the smallest says ? (it should be written on two 
seperate 
> > lines in very small letters)
>

In this case use that one, following my instructions



--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 
wrote:
>
> uhhmmm.... 
> 
> IN
> 4I
> 48
> RK
> 
> I guess...
> 
> Also another question - can I mount two of these diodes in a row, 
just 
> for greater safety, in case one goes off ?
> 
> 
> --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > Whau does the smallest says ? (it should be written on two 
seperate 
> > lines in very small letters)
>

Dammit.
Please look at this:
http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
is this the right order I should solder it? Or the diode should be put 
the other way round ?


--- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@...> wrote:
>
> In this case use that one, following my instructions

This is the right order.

--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 
wrote:
>
> Dammit.
> Please look at this:
> http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
> is this the right order I should solder it? Or the diode should be 
put 

> the other way round ?
> 
> 
> --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > In this case use that one, following my instructions
>

you should think of your fans before $

On Aug 12, 2006, at 6:21 PM, gil_we wrote:

> This is the right order.
>
>  --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...>
>  wrote:
>  >
>  > Dammit.
>  > Please look at this:
>  > http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
>  > is this the right order I should solder it? Or the diode should be
>  put
>  > the other way round ?
>  >
>  >
>  > --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
>  > >
>  > > In this case use that one, following my instructions
>  >
>
>  
>

<<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190018618288>>

huh ???


--- In kawai_analog@yahoogroups.com, league_of_james@... wrote:
>
> you should think of your fans before $
> 
> On Aug 12, 2006, at 6:21 PM, gil_we wrote:
> 
> > This is the right order.
> >
> >  --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@>
> >  wrote:
> >  >
> >  > Dammit.
> >  > Please look at this:
> >  > http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
> >  > is this the right order I should solder it? Or the diode 
should be

> >  put
> >  > the other way round ?
> >  >
> >  >
> >  > --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >  > >
> >  > > In this case use that one, following my instructions
> >  >
> >
> >  
> >
>

You don t want to run 2 or more diodes in series. Each diode will have a ~.7v junction drop, so if you start stacking them you ll lower the voltage to the CMOS

It works ! :) Thanks!



--- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@...> wrote:

>
> This is the right order.
> 
> --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> wrote:
> >
> > Dammit.
> > Please look at this:
> > http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
> > is this the right order I should solder it? Or the diode should be 
> put 
> > the other way round ?

Great ! ;)


--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 
wrote:
>
> It works ! :) Thanks!
> 
> 
> 
> --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > This is the right order.
> > 
> > --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> > wrote:
> > >
> > > Dammit.
> > > Please look at this:
> > > http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
> > > is this the right order I should solder it? Or the diode should 
be 

> > put 
> > > the other way round ?
>

Oh crap... more than a week has passed and some of the patches are 
lost again...
I can't stand this any longer :(


--- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@...> wrote:
>
> Great ! ;)
> 
> 
> --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> wrote:
> >
> > It works ! :) Thanks!
> > 
> > 
> > 
> > --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> > >
> > > This is the right order.
> > > 
> > > --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> > > wrote:
> > > >
> > > > Dammit.
> > > > Please look at this:
> > > > http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
> > > > is this the right order I should solder it? Or the diode 
should 

> be 
> > > put 
> > > > the other way round ?
> >
>

--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 



you must have a (short drain )of some kind going on


















wrote:

>
> Oh crap... more than a week has passed and some of the patches are 
> lost again...
> I can't stand this any longer :(
> 
> 
> --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > Great ! ;)
> > 
> > 
> > --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> > wrote:
> > >
> > > It works ! :) Thanks!
> > > 
> > > 
> > > 
> > > --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> > > >
> > > > This is the right order.
> > > > 
> > > > --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> > > > wrote:
> > > > >
> > > > > Dammit.
> > > > > Please look at this:
> > > > > http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
> > > > > is this the right order I should solder it? Or the diode 
> should 
> > be 
> > > > put 
> > > > > the other way round ?
> > >
> >
>

Did it have the same problem BEFORE replacing the battery ?


--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 
wrote:
>
> Oh crap... more than a week has passed and some of the patches are 
> lost again...
> I can't stand this any longer :(
> 
> 
> --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > Great ! ;)
> > 
> > 
> > --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> > wrote:
> > >
> > > It works ! :) Thanks!
> > > 
> > > 
> > > 
> > > --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> > > >
> > > > This is the right order.
> > > > 
> > > > --- In kawai_analog@yahoogroups.com, "sputnik979" 
<sputnik979@> 

> > > > wrote:
> > > > >
> > > > > Dammit.
> > > > > Please look at this:
> > > > > http://img99.imageshack.us/img99/6746/anodecathodewv5.jpg
> > > > > is this the right order I should solder it? Or the diode 
> should 
> > be 
> > > > put 
> > > > > the other way round ?
> > >
> >
>

Well, actually it's all jumbled up in my head. I remember that I'm 
having this problem ever since I became the owner of the Kawai. From 
the previous owner and from what I saw I know that the original 
battery has been replaced, just for the sake of prevention of 
leakage. But a new idea dawned on me. Can I mount a basket for 
two/three 1.5V AA batteries inside my SX240? They would be replaced 
every couple of months or so. Just like in Poly800 or Casio CZ.



--- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@...> wrote:
>
> Did it have the same problem BEFORE replacing the battery ?
> 
> 
> --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> wrote:
> >
> > Oh crap... more than a week has passed and some of the patches 
are 
> > lost again...
> > I can't stand this any longer :(

You can do that but why would you ?.... Search for the real cause for 
that problem and fix it. You might have a short somewhere draining 
the battery down.


--- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@...> 
wrote:
>
> Well, actually it's all jumbled up in my head. I remember that I'm 
> having this problem ever since I became the owner of the Kawai. 
From 

> the previous owner and from what I saw I know that the original 
> battery has been replaced, just for the sake of prevention of 
> leakage. But a new idea dawned on me. Can I mount a basket for 
> two/three 1.5V AA batteries inside my SX240? They would be replaced 
> every couple of months or so. Just like in Poly800 or Casio CZ.
> 
> 
> 
> --- In kawai_analog@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > Did it have the same problem BEFORE replacing the battery ?
> > 
> > 
> > --- In kawai_analog@yahoogroups.com, "sputnik979" <sputnik979@> 
> > wrote:
> > >
> > > Oh crap... more than a week has passed and some of the patches 
> are 
> > > lost again...
> > > I can't stand this any longer :(
>

Oh crap... more than a week has passed and some of the patches are 
lost again...
I can't stand this any longer :(

You have more acid damage to repair. My 240 did the same thing until I extensively repaired the entire area. You have work ahead of you......

-- 
___________________________________________________
Play 100s of games for FREE! http://games.mail.com/

You can do that but why would you ?.... Search for the real cause for 
that problem and fix it. You might have a short somewhere draining 
the battery down.

He never said the battery was dead. I assume its not and there's traces/solder joints that need to be repaired. Can the OP upload hi-res pix of the CPU pcb to the "files" section? I can tell just by looking at it if there's corrupt solder. Spent all day yesterday repairing acid damage on a pinball cpu brd....


-- 
___________________________________________________
Play 100s of games for FREE! http://games.mail.com/