[sdiy] Glowing diode on Casio CT-510 analog board?

Adam (synthDIY) synthdiy at adambaby.com
Tue May 23 12:02:31 CEST 2023



> On 23 May 2023, at 5:52 pm, Roman Sowa <modular at go2.pl> wrote:
> FWIW, back in the 90's I used 4 LEDs to create expo converter to drive VCF. Turned out to be accurate enough for the filter. And it looks so cool when played, especially with deep LFO. Too bad I have to open the case to see it.


(falls off chair..)

Roman, you know you can't get away with statements like that without showing us photos! C'mon!

A
















> Roman
> 
> W dniu 2023-05-23 o 02:53, Benjamin Tremblay via Synth-diy pisze:
>> Here it is.
>> Benjamin Tremblay
>>> On May 22, 2023, at 8:41 PM, Benjamin Tremblay <btremblay at me.com> wrote:
>>> 
>>> Sorry if this is way way way off topic. I’m trying to fix this Casiotone keyboard and there are no schematics. The power supply seems to be putting out around 4 volts. The logic board runs but the 4558, 4066, and power amplifiers seem inert.
>>> I’m trying to trace the power supply. Unlike most Casios from the 80s, the 5 volt regulator is just a zener diode, not a 7805. There’s one more non-zener diode on the board, and it’s faintly glowing red (!)
>>> I know all diodes emit radiation when they are operating, but this one has such and led-red color.
>>> Were such diodes ever used to indicate an overload on the board? I was more interested in fluorescent hair gel than power supplies  when this keyboard was made.
>>> <image2.jpeg>
>>> 
>>> (Lower left corner, a normal looking glass diode)
>>> Benjamin Tremblay
>>> 
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at synth-diy.org
>>> http://synth-diy.org/mailman/listinfo/synth-diy
>>> Selling or trading? Use marketplace at synth-diy.org
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org




More information about the Synth-diy mailing list