I'm back at the CS-80 repair. I ended up removing TU from the KAS board but before I was getting 'nearly' the same pitch across the whole keybed, and the voltage at TU was 13.37v. I removed TU and the pitch totally changed on the keys. I was getting much more variation of pitch across the keybed, just octave issues. I replaced TU back onto the KAS board and the pitch stayed pretty much the same as this new way now. Here is a clip of me playing every key up the keybed: http://www.heathfinnie.com/media/cs80issue.mp3 The voltage at TU dropped some as well after removing it and the resoldering it. It's now at 10.37v and VR3 on the BA board has 0 effect on this voltage like it should. I should also note that the tuning knob and pitch ribbon still have no effect on the pitch. I tried to do the adjustment of the KAS board and here are the voltages I'm getting: TU: 10.37v (should be 4v) Octave Ladder network - should be 125.0mv at Pin 13 on IC2 I'm getting -4.10v Voltage follower: Pin 6 IC3: Should be 125.0mv, I'm getting 2.55v Note Ladder Network: Pin 38 IC2: Should be +132.4mv, I'm getting 2.55v On the BA board I've replaced IC1, 2, 3 and 4. TR29 and both Fets. I highly doubt the problem is on the KAS board as I replaced it entirely from another one and the problem was exactly the same. Thanks! --- In yamahacs80@yahoogroups.com, "willgregori" <will.gregory@...> wrote: > > Had the same problem, on my cs80 TR29 was a broken on the BA board, > > good luck > > --- In yamahacs80@yahoogroups.com, "Heath Finnie" <heathfinnie@> > wrote: > > > > This is a big question here. The CS-80 I'm working on will barely > change pitch all the way up > > the keyboard now. Some keys will play a little lower but not much. > Now here are the > > symptoms: > > > > I replaced most all the IC's on the sub board. I replaced the > entire KAS board with a working > > one. Problem does not change. > > > > The pitch ribbon is having no effect on pitch. Neither is the pitch > knob. > > > > The channel 2 detune IS working as is the footing sliders. > > > > Ring modulator is working, sub oscillator is working and so is all > the waveforms. > > > > Any of the tech guys able to help? > > > > Thanks! > > >
Message
Re: stumped - no variation of pitch!!!
2008-12-26 by Heath Finnie
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