Hello rperalta78

> when i turned on my korg MP4 last week i noticed that there was a
> little smoke coming out of what appears to be the power supply(its
> says on top 250v fuse)and it was dead. im not familiarized with all
> this electronics so i was hoping i could find someone here that
> understands something about VINTAGE GEAR or that could at least help
> me identifiy the problems.

I think: If you are not familiar with electronics basically, then you
definitely should keep your hands of power supplies. Each mistake you
will do (and you will do mistakes) on a powersupply will kill the rest
of the synth at least - and assumingly it might kill also you.

If I misunderstood and you are only not familiar with analogue
electronics, then unplug all cables which connect the powersupply with
the other pcbs. Then switch on the synth measure first AC at the
transformer out, then DC at the large capacitors and then the regulated
DC at one of the connectors.

The service manual is available at several places. I host it on my site
too: http://fa.utfs.org/diy/korg_monopoly/index.html

EXPLICIT WARNING: if a single rail of the double rail power is missing
you will kill several rare integrated circuits like the SSM2044 VCF and
the SSM2033 VCO. The VCOs are close to impossible to get today; the MP
is nearly worthless without them. If you think you are not technically
skilled enough then DON'T SWITCH THE MP ON again and bring it to a tech.

Florian