Korg Poly800/EX800 Users

I didn't try sysex (don't think the stock Poly 800 1 has any sysex
capability), but I did try loading up the factory patches via the
cassette interface. I had to do it blind though since the display is
dead and it did not appear to have done anything. I believe that the
input switches are also dead as they are on the same board as the
display LED's. I also tried blindly adding a manual patch, but no luck
there either. I may try at least hooking up the Midi side anyway to
see if at least the Midi In/Out is responding.

<<aaRoN>>

--- In korgpolyex@yahoogroups.com, "Erik Hines" <sablerock@...> wrote:
>
> Have you tried sending a SYSX dump of the original patches to the
> Poly? I have found MANY a poly\ex that were sold at garage sales and
> thrift stores because no-one could figure out why they didn't hear any
> sound, or only heard noise and blips. After a Sysx dump, 8 times out
> of 10 it'll fix the problem...
> 
> The poly's memory is battery backup, so there is decay after years of
> no-use and makes the patches corrupt.
> 
> Erik
> 
> 
> --- In korgpolyex@yahoogroups.com, "selloutdesigns" <aah_public@>
> wrote:
> >
> > Stop me if you've heard this one before...Bought an "As Is" Poly on
> > eBay. Cleaned it up, plugged it in a lo and behold no display. Sound
> > is present at the headphone jack about 30 seconds after turning on.
> > It's a frequency sweep from low to high (sounds almost like the whoosh
> > of a jet engine starting) followed by constant white noise. This sound
> > is affected by turning VR1, VR2 and VR3 trimpots.
> > 
> > I'm okay at basic electronic troubleshooting and repair, but have run
> > out of ideas, so wondering if anyone has had a similar experience. I
> > have pretty much determined it is not a power supply circuit issue (as
> > I was hoping when I bought it). All the IC's I sampled are getting
> > correct power. Also on connector KLM596 CN6A, Pin 6 shows 4.98v, Pin 8
> > shows -5.07v and Pin 9 shows 9.44v, all of which I believe to be
> > normal and show the power section is working OK.
> > 
> > Unfortunately, I do not have access to a scope. Is it even worth going
> > any further at this point without one? In a previous post where
> > someone had a similar issue, it was mentioned that if the RES6.5 clock
> > was not running this could cause a dead display. I did check RES
> > 5.5,6.5 and 7.5 pins on M80C85A chip. RES7.5 pin shows 1.45v, but the
> > other two are 0v or at least < 1 mv.
> > 
> > Any ideas or suggestions on where to look next?
> >
>