> From: sndgroom@...
>
> yes, I have a scope, thanks for the tip, I'll try that.
> Regarding the sliders behavior, it is erratic everywhere,
> pedal and levers included.
> The sliders practically do not affect anything, just towards
> the mid position, they jump to random values.
> If left in that position, my Polaris starts modulating
> everything, something like a S&H on filters and some other
> craziness, like drunk.

Yeah, it sounds like it's not the sliders. That's good, because everything else is easy to replace. It could be the ADC0804 converter, but as long as you have the scope, you may be able to figure out what's wrong.

There should be 0V and 5V on the two ends of the sliders, and each wiper should produce a clean 0V to 5V range as you move the slider. Then, if you look at the ADC line, you should see a time-multiplexed version of all the sliders and other inputs. That pattern should be duplcated on the input to the ADC (Z54-1 or Z53-6). Make sure there's 2.5V on the reference input (Z54-7 or Z53-9). If everything looks cool, then I'd suspect Z53. If there's a problem in the muxes, you'll probably see something wrong in the ADC value, or perhaps even at some of the slider wipers.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...