My EDU09 has been functioning for about a month. Today I was using it on a 5V-powered FM radio circuit, and at the specific point the measurement showed just over 1V DC. I made a needed modification and came back, and have had no response from the unit since.
I certainly did something wrong, but that is for another time. What I would like is to be able to repair, or at least understand what could be wrong with the unit. I have been through the forum messages, but there is not enough to help me. For example, I saw a reference about 3.3V on pin 1 of IC3 - it has that.
So - is there some way for me to troubleshoot the board to narrow the problem, as in the example I cited above? I am hoping for key positions on the board where I should have a specific voltage, or ???
I am also hoping the problem resides in one of the IC’s, and that I can get a replacement for it.
Everything checks to the references you sent except IC 1, pin 9, which has 0 volts. By the datasheet this is Address Select S2, yes? I had uninstalled the EDU09 application, so today I reinstalled it. It complained about seeing another instance, but I told it to go ahead. When I remeasured IC 1, pin 9, it had 3.3 volts. So I tried using the scope, and it is functioning again just as it had before.
I want to thank you for your help. It appears to be software related (?), or maybe it needed some time off to have something reset (?), or it just got scared when it found out I had told on it to its parents.
