Korg Poly800/EX800 Users group photo

Yahoo Groups archive

Korg Poly800/EX800 Users

Index last updated: 2026-04-12 15:09 UTC

Message

Re: [korgpolyex] Poly 800 A/C Adapter Issue

2009-03-10 by TheTravelSource Fes

Thanks for the ideas Gordon. The power supply I have is fine. Tip negative, 9v, sufficient amperage. When I test the circuit at the pin inside the Korg, I get voltage. I am wondering where to go next...a diode, a resistor, etc.

--- On Tue, 3/10/09, Gordon JC Pearce wrote:

From: Gordon JC Pearce
Subject: Re: [korgpolyex] Poly 800 A/C Adapter Issue
To: korgpolyex@yahoogroups.com
Date: Tuesday, March 10, 2009, 6:45 AM

thetravelsource wrote:
> My Poly-800 works fine on batteries but I have not been able to use the A/C adapter for years. I think someone once fried the circuit with the wrong adapter or polarity and I am wondering if anyone has had a similar problem and knows where to begin to repair.

Are you sure the power supply is working? If it's not, then there's
your answer. I think they're negative-to- middle, 9V - same as
Boss/Roland/ Kawai, not like Yamaha.

The power connectors on the Poly-800 (and indeed anything that uses that
type of connector) are usually pretty reliable, but tend to fail such
that the batteries don't work and an adaptor does! What happens is that
there's a pin up the middle for one connection and a springy metal strip
that touches the outside of the plug when it's in, or another metal
strip connected to the battery (so it acts as a switch). The only way I
can see for the thing to work on batteries but not with a working mains
PSU is either the pin is broken, or there is a bad solder joint between
the tag with the pin and the board.

> I am finding it hard to search the group messages via yahoo for similar problems. Perhaps there are no other posts but if someone knows of an answer on this group, please point me to it.

Yahoo Groups search is knackered. Utterly useless.

Gordon

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.