Edu09 stopped working

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.

Thanks.