[sdiy] Weird Prodigy problem

[David G. Dixon]

> I have a weird problem with a Prodigy that I have here to 
> have cv/gate installed.
> I'm not sure if it's anything caused by the mod or something 
> that has occured for unrelated reasons.
> 
> The +12V power drops to about 10V when you press a key, 
> jumping back to +10V about half a second after release.
> Strangly enough, it occurs less often once the Prodigy warms 
> up, so it's not a short somewhere in the gate circuit.
> 
> I have already replaced the power supply capacitors and the 
> 78M12 for good measure, so it's most likely something in the 
> Prodigy that is causing this.
> 
> Any suggestions?

My first thought is that your gate circuit is pulling an enormous amount of
current.  I've seen gate circuits on the web which are candidates for this.
However, the warming up business is a bit mysterious.