Korg Poly800/EX800 Users

Hi everybody,

I just got my first Poly-800 and it is a lot of fun.  I have one concern
though... it doesn't seem to work with any AC adapters.  It works fine
with batteries.  But if I ever try to operate it with the AC adapter
plugged in, it simply won't turn on.  As soon as I pull out the AC adapter
it turns on and operates off the batteries.

The eBay seller told me that the Poly-800 uses a longer-tipped AC adapter
than most, so I will need better than a garden-variety adapter.  This
doesn't seem very plausible but I'm willing to believe him (it's a happier
idea than taking it apart after only the first week).

The sale didn't include the original adapter so I've had to improvise.  I
have tried a Sony 9v DC negative-tip 300ma and a Roland 9v DC negative-tip
1000ma.  Both adapters work with other gadgets.

The AC jack does not seem to be loose, and light wiggling has no effect on
it.

Any help appreciated.

Thanks
T