We have identified a rare malfunction with Cortado serial numbers ZD1201-ZD1251. There may be as many as five or six Cortados in circultation that may exhibit this problem. If your Cortado delivers no signal at all, though you have checked your work carefully, or if it produces a very weak signal, or if it only produces a signal when you hit the piezo really hard, then this Service Bulletin is for you. In essence, the FETs are not biased properly. In the fix, we show you how to change the resistance at R8 to fix the problem.
Get Service Bulletin 15.11.1 here!