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Hello Johannes,
thank you.
I've tested continuity between IC32 pin 15 and IC 22 pin 22 and it's OK.
I've played quite a lot the synth (what a sound!) last night to check if other parameters don't work but the synth is fine and all controls respond. Saving a patch takes into account all parameters.
About the RAM accesses, I think I need a few informations. I have a scope that I use to calibrate delays or flangers that i build. Checking RAM is another story.
So in a few words, how am I going to test RAM using my scope? Which signal do I have to expect?
sorry for these questions...
thanks!
Ed.
---In PolySix@yahoogroups.com, <johau@...> wrote:Apparently the addressing of the patch RAM has a fault. This could be
a long term subsequent fault from the leaked battery.
There could be a number of reasons causing wrong adressing; the RAM
chip itself is a candidate, I had a few chips failing.
The high address line is an I/O port line of the 8048 MPU, which is
also used as a selector for the analog control voltages (P21). So if
the analog controls work this signal is OK. It could be interrupted
(e.g. by corrosion). You can check this with a DVM:
IC32 (RAM chip) pin 15 to IC 22 (CPU) pin 22.
With an oscilloscope you could easily check RAM accesses, trigger on
the chip select (pin 8) and check one (address) line after the other
while writing or reading to / from the RAM (e.g. recalling a patch).
Good luck!
JohannesOn 23.11.2013 14:57, djangowes@... wrote:
>
>
> Hello,
>
>
> forgot to add some things : my P6 had the battery issue. It has been
> repaired before I've had it, 4 years ago. I've changed all electrolytics
> in the power supply section. It has worked perfectly during these 4 years.
>
> I've tried to save a new preset, bank A, preset 5. The P6 saved it but
> it saved it also on bank A,preset 1. So it seems that half of the memory
> does not work. Could it come from the battery, or one of the memory
> component has failed (where to check?) ? I'm a bit confused as I don't
> know how the memory saving process works. If someone has some knowledge
> about this, that would be really helpfull.
>
>
> thanks,
>
>
> Ed.
>
>
>
> ---In PolySix@yahoogroups.com, <djangowes@...> wrote:
>
> Hello,
>
> Today my P6 has begun to behave strangely : considering each bank
> A,B,C,D the first 4 presets (1,2,3,4) have been "duplicated" to the 4
> last presets locations (5,6,7,8).
> Otherwise, the synth seem to work fine.
> Maybe someone had this issue in the past... or maybe some P6-specialists
> in here can help me and tell me where to check in my favorite
> synthesizer. KLM367 maybe, where the "brain" is...
>
> thanks for any kind of help.
>
> Ed.
>
>
>