KORG POLY-800 general help 2021

deathnote · Post by **deathnote** » Fri Jan 08, 2021 10:19 pm

Hello all,
First day on forum.
I have a Korg Poly-800 I have not powered up in 30 years until I tried today.
I'm well aware that the memory & programs are dependent on the batteries.
But I expected to see some indication of power, but not seeing anything.
I'm using the Korg 9V AC adapter.
Also, the unit was never damaged, was stored indoors in a hard shell custom made case.
And it worked last time I used it.
If there is any chance it can power-up I would like to give it away, or sell it.
It's a beautiful instrument, and would be shame to trash it, but I want to get rid of it.

voip · Post by **voip** » Sat Jan 09, 2021 5:59 pm

30 years is a long time for equipment to sit without being powered up. One thing that happens over that length of time is that electrolytic capacitors lose their thin electrolytically formed insulating layer between the positive and negative plates. Applying full voltage to these can lead to them giving out their magic blue smoke. There are various recipes around describing the reforming procedure for old electrolytic capacitors. Some involve taking the capacitors out and reforming using a suitably rated power supply and resistor. Another method involves gradually increasing the supply voltage to the main power input over many hours.

The power supply input expected by the Poly-800 is 9V DC, not AC. AC current will wreck the Poly-800 supply input components and probably other parts of the circuit too.

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deathnote · Post by **deathnote** » Sat Jan 09, 2021 7:27 pm

voip,

Well yes even with well cared for servers the first thing to go is usually a capacitor.

By AC adapter I meant AC/DC, the label says KORG, and the output is 9V, and I believe 700 mA.

Amazingly I found the cassette tape to re-load the basic programming.

As I'm inclined to give it away "as is" and my Westbury guitar Amp. I found a nearby recording studio who might be interested.

But thanks for your support.

voip · Post by **voip** » Sat Jan 09, 2021 7:45 pm

Although with servers, the issue is often capacitor rot or plague, which became an issue with the chemistry of certain electrolytics manufactured over several years, starting from around 2000. The Poly-800 came out before that time.

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deathnote · Post by **deathnote** » Sat Jan 09, 2021 7:57 pm

That makes me wonder which devices had the more reliable capacitors: servers manufactured around 2000, or KORG Poly-800 era devices over 20 years earlier.
Whatever it I would hope current era capacitors are better.

Well I enjoyed my KORG the short time I used it even though I'm not much of a musician.
And I did learn something about the actual synthesized wave forms as well back then.

hermanmusic · Post by **hermanmusic** » Tue Jan 12, 2021 1:48 am

Could your power adapter be bad? Have you tried to power it on with batteries?

deathnote · Post by **deathnote** » Tue Jan 12, 2021 1:58 am

I don't think so, and no.
My volt meter died a 2nd death so I tested the KORG AC/DC 9V adapter by touching the output jack/plug to my tongue.
And yep - it's got power.

This week is the first time I've attempted powering the unit in 30 years.
So the batteries are long dead.

Hence our other friend's suggestion about capacitors.
I contacted a couple of local recording studios, and they aren't even interested in it nor my Westbury guitar amp for free.

So I guess it's all junk now.
Thanks for your concern.

hermanmusic · Post by **hermanmusic** » Fri Jan 15, 2021 11:54 am

Are dead batteries still in the instrument? Have they leaked? If they haven't then why not try fresh batteries? If they have leaked it is possible you can clean the contacts. You will have to take it apart to clean both ends of the battery compartment (I did this once, a trillion years ago), but it's worth a shot.