Korg Forums

[denmla]

Prophecy is alive!



Control resistor in place of this little blue R2 resistor went and synth would go to sort of safety mode. Replaced with new and all works.

Thanks man for helping out and hopefully somebody in the future will learn something from this thread!

Cheers

[voip]

Great outcome :-) Did the resistor go open circuit? It didn't look burnt out in the original images.

A lot of Korg power supplies fall into a general, broadly similar basic design, so this solution may well apply to other keyboards and sound modules, so should remain useful as long as this forum has legs. Too much of the goodness in the internet is lost when a server is turned off, or a hosting contract is not renewed. Long may this forum continue. It is a precious thing. I like the way the solution to the problem was not down to any one person but to a collective use of ideas and observations. Brilliant!!

The Prophecy PSU differs from many inboard PSUs in that it only has two outputs, and the +12V regulation is not on the PSU itself, but on the mainboard. Most Korg internal PSUs have three outputs, most often +5, -12 and +12V, with regulation on the PSU board itself.

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[denmla]

Agreed 100% forums like this have to prevail!

Also correct is that resistor went open circuit! I have it in my hand and you couldnt tell anything is wrong with it without measuring it.

Have a good one