e-licktronic Forum

I need help figuring out where to look next. The entire NAVA is built and working, and the MT voice was working properly until I tried troubleshooting the decay pot. Now I'm afraid I may have broken a component or trace. The output from the voice is just a constant stream of noise, with very faint clicks in the background where triggers would be. When I probe with the oscilloscope I don't see waveforms for any of the VCOs or envelopes and there are no square waves present on IC22. All of the SIL amps are getting the proper voltages and I have tried replacing the ICs. I checked the via near VR14 and there is no short there.

Where would you suggest looking next? Any voltage references that would be helpful in troubleshooting?

Thanks!

I ended up finding what the issue was. One of the 2SC2603 transistors got burned out and needed to be replaced. In the process of troubleshooting, I did manage to find 2 broken traces and fixing those resolved the issue I was having with the decay.

Now I appear to have a fully-working Nava, and could not be happier!