Korg Poly800/EX800 Users

Hi ive just bought a broken poly 800, my intention was to fix it and
convert it so i can have it rack mounted.
Unforunatly it has nothing on the display but when i switch it on i
can hear power.
Ive taken it apart and with my basic knowledge tried to fix it but
now realise i have two choices.
Sell it to an electronics expert or buy another faulty one and
hopefully use parts from both to make a good un.
So my question: does anyone here (from the UK) have a faulty one to
sell or know where i could get it cheaply repaired.
thanks

Hi
Thanks for the info i did have a problem with my old poly with he
battery and that is now fixed but my other one has nothing on the
display but i can hear a very faint power hum when i switch it on..
just the sound of the power going through the circuits.
I have pressed the keys and nothing happens :(
Maybe this poly with no display is gonna be difficult to fix?


--- In korgpolyex@yahoogroups.com, Dan Brewton <dannobe123@y...>
wrote:

> Greetings
>
> I've repaired several of these machines....the GROUP Korgpolyex

has tons of past

> forum discussions about the usual ailment with these.....most

often just the internal

> 3 volt Lithium Battery on the main PCB is dead, losing all its

presets......so there is

> nothing in recent memory to work with, thus it appears dead, but

in all probability you

> just re-program into "11" any voice parameters that produces more

than noise......

> then save this to a differnet patch#, and then youll know if its

worth while to proceed....

> If that works, then install a new battery onto the circuit board

and program the remainder

> of the patches......check out the files area of this group , as

well

> Cheers,
> Dan
> Dannobe123@y...

Hi Dan
Thanks for the info thats very interesting.
I know the external supply is ok because i use it with my working
poly 800. Im now thinking about checking the internal power supply
and am quite handy with a soldering iron. Do you know what i should
test or replace, i have downloaded the schematics but dont know the
best place to begin.
Regards
Neil

--- In korgpolyex@yahoogroups.com, Dan Brewton <dannobe123@y...>
wrote:

> Hi......... The next highest Probability, to me, is the Power

Supply within the Unit....

> These do fail occasionally.....Internally there is both a +5 volt

and -5 volt regulated

> supply system ,derived from the 12DC volts input

externally......sometimes people get lazy and plug most anything
into the jack, and , wallah, its toast.......but one saving grace is
this one dies without allowing massive over-voltage to the sensitive
logic circuits that need no more than 5 volts.....usually......cant
know for sure until the supply is fixed, then you get to discover if
the 'next layer' survived......These Power supplies are a bit
difficult to repair... known as "switchers" .....pretty
tricky......some guys I know just gut it out and

> replace with external supply, regulated +/- 5

volts.......naturally you need the schematics

> for all this....... let me know !
> Cheers
> Dan