A good friend of mine owns a Ketron SD1 and it has problems with the power supply.

Who can help me to get hands on the schematic drawings?

The only person I know is TWD, not certain he will have a circuit drawing for it, can't you sort it out without a drawing, what's wrong with the PS.

Hi Tony,

Well, the original toroidal transformer was replaced by an unknown 'technician' with one that has not the same voltage outputs.

(Original transformer says : 1 x 12V, 2 x 16.2V The replacement one measures 1 x 16 and 2 x 14.6 V AC while active in circuit)

On top of that he messed up the wiring and I'm afraid he connected ground-wiring to the secondary AC circuit. Now there is a HUGE humming noise and I want to get rid of this.

In fact I would like to know how the transformer should be connected on terminals 1 - 8 on the PC board (CN1)

TWD will know this he will probably have a photo of it somewhere. See if he sees this thread.I think you have a grounding problem.

I have schematics. will email the PSU page over to you.

edit: your email address is not on here what is it?

[This message has been edited by Tonewheeldude (edited 11-27-2010).]

That would be great!
My email (removed)

Roel

[This message has been edited by kla4 (edited 11-28-2010).]

Thanks TWD

Tony

email sent - might want to edit your email address out of the above post now to avoid spam.

Email arrived, thank you very much Darren!

Problem solved and SD1 working fine again.

[This message has been edited by kla4 (edited 11-29-2010).]