Ensoniq KS-32 Loud Humming When turned on

This unit hums real loud as soon as it is turned on. Any controls do not have any effect of what it does. Does anyone have any ideas what could be wrong or where to start? Thank you!

I’m guessing power supply trouble.

Is the humming through the audio outputs, or is it a physical humming that you hear, even with no audio cables connected? A physical hum usually comes from the power transformer.

If you are technically inclined and have a voltmeter, you can open up the keyboard, and maybe hear close-up whether the transformer itself is humming. (Don’t poke ears or fingers onto live voltages!) And you can measure the outputs of the power supply to see if it is creating the correct voltages.

Thanks for the reply Sam. I had it plugged into an amp and thru that made the noise. Turning down volume or trying to change sounds had no affect. I still have it in storage. Once I get my paws on it I will check the connections and burnish them, check for cold solder joints to see if it gets better…

So the display looks normal - i.e. it shows a program name? And when you play, do you hear that sound at all, or is it just hum?

Hi Sam, it only emits a loud noise/buzz thru the outputs. Trying to change vol on the key did not change loudness. I think it showed normal settings on the display, but I will have to get it out of storage to verify… I can let you know one I do. Feel free to comment if you have additional comments.
Thx Andrew

Any luck with this? I have exactly the same issue. Worked perfectly until yesterday then just buzzing/humming. Unlikely a power board issue as everything on the display is normal. Keys, volume etc. Don’t register at all. Battery good. Fuses all good. Cheers.

Sorry, haven’t been here for a while due to health issues and moving. I have the ks-32 here now, and shelved it due to other priorities. I appreciate you reaching out. I haven’t had a chance to look at it further. I forgot someone’s suggestion, perhaps to reheat some of the solder joints or reseat connectors first? I see you wrote some time ago. I apologize for the delay in responding. Did you have any luck with yours since then? Seems like other models were more popular than ours so didn’t get many responses. It was a nice keyboard when it worked. I hate tossing things and like to keep it in working order. Please let me know your status and I will try to do better in my correspondence. Thank you and good luck. Andrew