Hi, thanks to Steve, I checked the resistor at first.
It was dead.
I replaced it and needed some calibration work to bring the VCO4 back to the same tuning as the other 3 VCOs. Now the 4 VCOs work stable in any octave and waveform.
Please notice that if a resistor is dead in any VCO, this oscillator comes slower than the others to the perfect & stable tuning. The time depends on the room temperature, it may comes earlier, especially in the summer.
---In korg_mono-poly@yahoogroups.com, <dir_marillion@...> wrote:
Hello,
To a recent repair of my Mono/Poly, engineer had to remove the VCO thermal grease over the chip. Then he replaced it with another compound/paste and for a few weeks the instrument was working perfect.
Now, when I turn on the Mono/Poly the first 3 oscillators come to the same tuning after 10-15 minutes (the most) but the 4rth VCO comes synchronizes with them after 25-30 minutes.
What kind of thermal paste do you suggest for the Mono/Poly?
Do you suggest to use this paste to all 4 oscillators or only to VCO 4 ?
Will this thermal paste work or VCOs need a special paste?
http://www.radioshack.com/product/index.jsp?productId=2216880
Thank you very much
To a recent repair of my Mono/Poly, engineer had to remove the VCO thermal grease over the chip. Then he replaced it with another compound/paste and for a few weeks the instrument was working perfect.
Now, when I turn on the Mono/Poly the first 3 oscillators come to the same tuning after 10-15 minutes (the most) but the 4rth VCO comes synchronizes with them after 25-30 minutes.
What kind of thermal paste do you suggest for the Mono/Poly?
Do you suggest to use this paste to all 4 oscillators or only to VCO 4 ?
Will this thermal paste work or VCOs need a special paste?
http://www.radioshack.com/product/index.jsp?productId=2216880
Thank you very much