Random Popping/ crackling sounds when not playing synth

[Musicwerks]

Hi all,

I have a 3rd hand Maxikorg which is showing some problems.

After warming up and playing for sometime, I will start hearing popping and crackling sounds in the background on both upper and lower sounds when I am not playing the synth. The notes will also get an extra popping effect on the attack when I play.

Then I would need to switch off for a while. It becomes okay after that again.

Can anyone advise me what might be the potential problem?


Refurbishment done thus far
a) The two SK30 transistors have been replaced.
b) Power SUPPLY lines have been recapped.
c) the lower voice VCO panel has been all been recapped.

Thanks in advance
Musicwerks

[adhmzaiusz]

Sounds to me like a cold solder. You'll have to examine the boards to find it.

[sawwave]

I had a similar problem with my Microkorg XL. There was a faulty ground connection between two boards. Not that simple to figure out, but easy to fix.

[garranimal]

I had something similar going on with a Korg Delta, it was a dying capacitor in the filter circuit. It was very hard to track down.