e-licktronic Forum

Ok, so the story goes last year all of a sudden my Yocto started playing the cowbell on every step, I eventually got that corrected and then all of a sudden it started acting like the shift button was permanently stuck on. That was traced down do a dead shift register IC 7 thanks to help from you guys, after that it more or less worked well, but I couldn't use it in expander mode as a module, it would trigger a few sounds but it did not behave the way it is supposed to. That led me to now: I am pulling all of the original shift registers, socketing them, and replacing with new figuring that if the one went bad earlier another one may be responsible for the MIDI weirdness. Well, I've just replaced ICs 2 and 3, and after turning it on to test, now it will not play at all, multiple pattern select buttons can be lit at once, I cannot use init mode... it's totally crippled. I've tried several of each chip, I can't see any shorts, I've reflowed everything... this makes no sense to me

Does anyone have any suggestions? The digital part of this thing has been super buggy since I finished it, it has never worked reliably for long, so if anyone has any insight I'd love to hear it. I'm quite frustrated.

Thanks

Shane

I'll leave this up just in case it may help someone in the future, but I ended up suspecting that I broke a trace under a socket while removing the old IC's so I pulled the new sockets and that's exactly what happened. it was positioned perfectly so I couldn't see it with the socket installed, and just the tiniest nick with a screwdriver that split the trace. Oops. Now to see if it works in expander mode!

Final update- I replaced all sequencer shift registers with new ones and my Yocto works 100% perfectly now. I'm not sure what happened that fried them, but all is well at this point. The symptom was that no mater what MIDI note was sent while in expander mode, all of the cymbals would trigger.

If you end up having to pull IC's be very careful while prying them up, most have traces running underneath them in the area you will be prying on.