[sdiy] Broken Siel Opera 6, any ideas?

[Roy J. Tellason]

On Tuesday 26 August 2008 18:05, Mattias Rickardsson wrote:
> When I look on different CPU pins on the oscilloscope, many of them
> seem to "blink" in the sense that they are 0 V for a while and then
> quickly changing between 0 and 5 V for a while, and so on. This
> "blinking" occurs with approx 2 Hz. I can see similarly timed things
> going on in the multiplexing address lines, they are turned on and
> off at 2 Hz. The panel indicators can show similar blinks when
> buttons are pressed. The DAC doesn't seem to change its output value.
>
> I wouldn't really expect this to happen, unless the CPU has entered
> some quite useless state waiting for something else to happen... has
> anybody had a similar experience here?
>
> What more... the CPU runs quite hot, the SSM2031 VCOs run EXTREMELY hot.
> Power seems to be OK everywhere, I havent found any broken PCB lines
> or other components eaten by the battery acid. The synth has been
> lying under my bed for a couple of years, can it be the ghosts perhaps?

What's the power supply supposed to be,  and what are you measuring it as at 
the chips that are showing this odd behavior?  It almost sounds like 
something is bouncing in and out of thermal shutdown...

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