OBERHEIM SYNTH

hello

since it is a DCO the only possible fault should be the programmable 
interrupt timer 8254.

Florian


Am 04.11.2019 um 01:59 schrieb Andy Birko andy.birko@... [oberheim]:
> Tried to send a message before but it seems to have been lost.
>
> Picked up a used M6R with a couple bad voices. �Voice 2 was dead and 
> just needed a re-seat of the CEM chip.
>
> Voice 3 though - DCO 2 is all wonky. �Its pitch is way high and 
> doesn't track correctly at all. �When changing the frequency through 
> param 10 is generally trends in the right direction but any given 
> value might be higher or lower than the one before.
>
> I've probed around with a lousy scope a bit and it seems that pin 8 of 
> the voice 3 CEM is at the wrong frequency. �i.e. I checked pin 4 and 8 
> of all the chips and only pin 8 of voice 3 seems to be at the wrong 
> frequency. �As I said, it's a pretty lo usy scope so info is limited.
>
> Any thoughts on how to proceed?
>
> Thanks in advance!
>
> -Andy
> 


-- 
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