Korg Poly800/EX800 Users

ok, so now i can sound stupid. i bought this new back in the early 80's, the batteries are corroded and i can't find the internial battery. is it on or under the mother board ? any help would be welcomed.

andy

If you see no battery, you have the model with no battery.

See: http://analog.no/cms/index.php?option=com_content&view=article&id=50&Itemid=49

--- In korgpolyex@yahoogroups.com, "pizdof" <e_flat4me@...> wrote:

>
> ok, so now i can sound stupid. i bought this new back in the early 80's, the batteries are corroded and i can't find the internial battery. is it on or under the mother board ? any help would be welcomed.
> 
> andy
>

Depending on the version, this Poly-800 may not have an internal battery at
all. It would be on the CPU board between IC18 and IC19 if it has one. If it
is really old, this will be just empty space. If it is a bit newer, it may
have solder tabs where the battery would eventually go, but no battery. The
last ones manufactured just before the Poly-800 II actually had a CR2032
lithium cell soldered in there. I this is one of the earlier two types, it
would need some small modifications to the power circuit to safely install a
CR2032
 
Don B.

I now have opened my 800 too and spotted a version with solder pads, but no battery. Richard (www.analog.no) says, one should remove C87, C88 and C23. After examining the schematics at this point, I cannot imagine why this components should be removed, since the two condensors help avoiding spikes and losing memory when changing the battery and the diode protects the battery from being charged if the poly 800 is powered from the batteries in the compartment of the bottom. Or am I completely wrong there?

--- In korgpolyex@yahoogroups.com, "backshall1 \(dsl\)" <backshall1@...> wrote:

>
> Depending on the version, this Poly-800 may not have an internal battery at
> all. It would be on the CPU board between IC18 and IC19 if it has one. If it
> is really old, this will be just empty space. If it is a bit newer, it may
> have solder tabs where the battery would eventually go, but no battery. The
> last ones manufactured just before the Poly-800 II actually had a CR2032
> lithium cell soldered in there. I this is one of the earlier two types, it
> would need some small modifications to the power circuit to safely install a
> CR2032
>  
> Don B.
>

The capacitors can't hurt anything, although they are a bit redundant. C88
is actually useful to hold the patches during a quick battery change. You
said C23, but I assume you meant D23. D23 is good, since it allows the
memory to use the regular 5v supply instead of the lithium cell when the
synth is turned on. Do not remove it. D15 is required to protect the battery
from being charged from the regular 5V supply.
 
On the other hand, there are a couple of parts that do need to be removed:
R1, D1.
R1 must be removed to prevent the voltage from the AC adapter from getting
to the lithium cell.
D1 must be removed to prevent the voltage from the C-cells from getting to
the lithium cell. A CR2032 lithium battery is not rechargable and could
overheat and burn if R1, D1 are not removed.
 
Don B

  _____  

From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
Behalf Of microbugix
Sent: Sunday, March 13, 2011 4:22 PM
To: korgpolyex@yahoogroups.com
Subject: [korgpolyex] Re: battery on Poly-800


  

I now have opened my 800 too and spotted a version with solder pads, but no
battery. Richard (www.analog.no) says, one should remove C87, C88 and C23.
After examining the schematics at this point, I cannot imagine why this
components should be removed, since the two condensors help avoiding spikes
and losing memory when changing the battery and the diode protects the
battery from being charged if the poly 800 is powered from the batteries in
the compartment of the bottom. Or am I completely wrong there?

--- In korgpolyex@yahoogroups.com <mailto:korgpolyex%40yahoogroups.com> ,
"backshall1 \(dsl\)" <backshall1@...> wrote:
>
> Depending on the version, this Poly-800 may not have an internal battery
at
> all. It would be on the CPU board between IC18 and IC19 if it has one. If
it
> is really old, this will be just empty space. If it is a bit newer, it may
> have solder tabs where the battery would eventually go, but no battery.
The
> last ones manufactured just before the Poly-800 II actually had a CR2032
> lithium cell soldered in there. I this is one of the earlier two types, it
> would need some small modifications to the power circuit to safely install
a

> CR2032
> 
> Don B.
>

thanx for quick reply, Don.
For sure I meant D23, just a typo. So i'm glad I assumed to leave these 
components in place.

Many thanks for mentioning R1 and D1, I should have taken a look in the file 
"poly8batt" found in my folders which says the same. From the schematics I could 
not see that these 2 components are connected with the battery. I have to tell 
Ricard, since he did not mention these 2 on his website. If a lithium cell 
overheats and burns, it possibly will emit hydrofluoirc acid - this requires 
immediate medical attention on exposure!

 bye,
Dietmar




________________________________
Von: backshall1 (dsl) <backshall1@...>
An: korgpolyex@yahoogroups.com
Gesendet: Sonntag, den 13. März 2011, 23:24:29 Uhr
Betreff: RE: [korgpolyex] Re: battery on Poly-800

   
The capacitors can't hurt anything, although they are a  bit redundant. C88 is 
actually useful to hold the patches during a quick battery  change. You said 
C23, but I assume you meant D23. D23 is good, since it allows  the memory to use 
the regular 5v supply instead of the lithium cell when the  synth is turned on. 
Do not remove it. D15 is required to protect the battery  from being charged 
from the regular 5V supply.
 
On the other hand, there are a couple of parts that do  need to be removed: R1, 
D1.
R1 must be removed to prevent the voltage from the AC  adapter from getting to 
the lithium cell.
D1 must be removed to prevent the voltage from the  C-cells from getting to the 
lithium cell. A CR2032 lithium battery is not  rechargable and could overheat 
and burn if R1, D1 are not  removed.
 
Don B


________________________________
 From: korgpolyex@yahoogroups.com  [mailto:korgpolyex@yahoogroups.com] On Behalf 
Of microbugix
Sent: Sunday, March 13, 2011 4:22 PM
To: korgpolyex@yahoogroups.com
Subject: [korgpolyex] Re: battery on  Poly-800

  
I now have opened my 800 too and spotted a version with solder pads, but no  
battery. Richard (www.analog.no) says, one should remove C87, C88 and C23. After  
examining the schematics at this point, I cannot imagine why this components  
should be removed, since the two condensors help avoiding spikes and losing  
memory when changing the battery and the diode protects the battery from being  
charged if the poly 800 is powered from the batteries in the compartment of the  
bottom. Or am I completely wrong there?

--- In korgpolyex@yahoogroups.com,  "backshall1 \(dsl\)" <backshall1@...> wrote:

>
> Depending on  the version, this Poly-800 may not have an internal battery at
> all. It  would be on the CPU board between IC18 and IC19 if it has one. If it
> is  really old, this will be just empty space. If it is a bit newer, it may
>  have solder tabs where the battery would eventually go, but no battery.  The
> last ones manufactured just before the Poly-800 II actually had a  CR2032
> lithium cell soldered in there. I this is one of the earlier two  types, it
> would need some small modifications to the power circuit to  safely install a
> CR2032
> 
> Don  B.
>